clinical study vs research study

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What Are Clinical Trials and Studies?

On this page:

What is clinical research?

Why participate in a clinical trial, what happens in a clinical trial or study, what happens when a clinical trial or study ends, what are the different phases of clinical trials, questions to ask before participating in clinical research, how do researchers decide who will participate, clinical research needs participants with diverse backgrounds.

By participating in clinical research, you can help scientists develop new medications and other strategies to treat and prevent disease. Many effective treatments that are used today, such as chemotherapy, cholesterol-lowering drugs, vaccines, and cognitive-behavioral therapy, would not exist without research participants. Whether you’re healthy or have a medical condition, people of all ages and backgrounds can participate in clinical trials. This article can help you learn more about clinical research, why people choose to participate, and how to get involved in a study.

Mr. Jackson's story

Mr. Jackson is 73 years old and was just diagnosed with Alzheimer’s disease . He is worried about how it will affect his daily life. Will he forget to take his medicine? Will he forget his favorite memories, like the births of his children or hiking the Appalachian Trail? When Mr. Jackson talked to his doctor about his concerns, she told him about a clinical trial that is testing a possible new Alzheimer’s treatment. But Mr. Jackson has concerns about clinical trials. He does not want to feel like a lab rat or take the chance of getting a treatment that may not work or could make him feel worse. The doctor explained that there are both risks and benefits to being part of a clinical trial, and she talked with Mr. Jackson about research studies — what they are, how they work, and why they need volunteers. This information helped Mr. Jackson feel better about clinical trials. He plans to learn more about how to participate.

Clinical research is the study of health and illness in people. There are two main types of clinical research: observational studies and clinical trials.

Observational studies monitor people in normal settings. Researchers gather information from people and compare changes over time. For example, researchers may ask a group of older adults about their exercise habits and provide monthly memory tests for a year to learn how physical activity is associated with cognitive health . Observational studies do not test a medical intervention, such as a drug or device, but may help identify new treatments or prevention strategies to test in clinical trials.

Clinical trials are research studies that test a medical, surgical, or behavioral intervention in people. These trials are the primary way that researchers determine if a new form of treatment or prevention, such as a new drug, diet, or medical device (for example, a pacemaker), is safe and effective in people. Often, a clinical trial is designed to learn if a new treatment is more effective or has less harmful side effects than existing treatments.

Other aims of clinical research include:

Testing ways to diagnose a disease early, sometimes before there are symptoms
Finding approaches to prevent a health problem, including in people who are healthy but at increased risk of developing a disease
Improving quality of life for people living with a life-threatening disease or chronic health problem
Studying the role of caregivers or support groups

Learn more about clinical research from MedlinePlus and ClinicalTrials.gov .

Why join a clinical trial or study? infographic. Open transcript for full description

People volunteer for clinical trials and studies for a variety of reasons, including:

They want to contribute to discovering health information that may help others in the future.
Participating in research helps them feel like they are playing a more active role in their health.
The treatments they have tried for their health problem did not work or there is no treatment for their health problem.

Whatever the motivation, when you choose to participate in a clinical trial, you become a partner in scientific discovery. Participating in research can help future generations lead healthier lives. Major medical breakthroughs could not happen without the generosity of clinical trial participants — young and old, healthy, or diagnosed with a disease.

Where can I find a clinical trial?

Looking for clinical trials related to aging and age-related health conditions? Talk to your health care provider and use online resources to:

Search for a clinical trial
Look for clinical trials on Alzheimer's, other dementias, and caregiving
Find a registry for a particular diagnosis or condition
Explore clinical trials and studies supported by NIA

After you find one or more studies that you are interested in, the next step is for you or your doctor to contact the study research staff and ask questions. You can usually find contact information in the description of the study.

Let your health care provider know if you are thinking about joining a clinical trial. Your provider may want to talk to the research team to make sure the study is safe for you and to help coordinate your care.

Joining a clinical trial is a personal decision with potential benefits and some risks. Learn what happens in a clinical trial and how participant safety is protected . Read and listen to testimonials from people who decided to participate in research.

Here’s what typically happens in a clinical trial or study:

Research staff explain the trial or study in detail, answer your questions, and gather more information about you.
Once you agree to participate, you sign an informed consent form indicating your understanding about what to expect as a participant and the various outcomes that could occur.
You are screened to make sure you qualify for the trial or study.
If accepted into the trial, you schedule a first visit, which is called the “baseline” visit. The researchers conduct cognitive and/or physical tests during this visit.
For some trials testing an intervention, you are assigned by chance (randomly) to a treatment group or a control group . The treatment group will get the intervention being tested, and the control group will not.
You follow the trial procedures and report any issues or concerns to researchers.
You may visit the research site at regularly scheduled times for new cognitive, physical, or other evaluations and discussions with staff. During these visits, the research team collects data and monitors your safety and well-being.
You continue to see your regular physician(s) for usual health care throughout the study.

How do researchers decide which interventions are safe to test in people?

Before a clinical trial is designed and launched, scientists perform laboratory tests and often conduct studies in animals to test a potential intervention’s safety and effectiveness. If these studies show favorable results, the U.S. Food and Drug Administration (FDA) approves the intervention to be tested in humans. Learn more about how the safety of clinical trial participants is protected.

Once a clinical trial or study ends, the researchers analyze the data to determine what the findings mean and to plan the next steps. As a participant, you should be provided information before the study starts about how long it will last, whether you will continue receiving the treatment after the trial ends (if applicable), and how the results of the research will be shared. If you have specific questions about what will happen when the trial or study ends, ask the research coordinator or staff.

Clinical trials of drugs and medical devices advance through several phases to test safety, determine effectiveness, and identify any side effects. The FDA typically requires Phase 1, 2, and 3 trials to be conducted to determine if the drug or device can be approved for further use. If researchers find the intervention to be safe and effective after the first three phases, the FDA approves it for clinical use and continues to monitor its effects.

Each phase has a different purpose:

A Phase 1 trial tests an experimental drug or device on a small group of people (around 20 to 80) to judge its safety, including any side effects, and to test the amount (dosage).
A Phase 2 trial includes more people (around 100 to 300) to help determine whether a drug is effective. This phase aims to obtain preliminary data on whether the drug or device works in people who have a certain disease or condition. These trials also continue to examine safety, including short-term side effects.
A Phase 3 trial gathers additional information from several hundred to a few thousand people about safety and effectiveness, studying different populations and different dosages, and comparing the intervention with other drugs or treatment approaches. If the FDA agrees that the trial results support the intervention’s use for a particular health condition, it will approve the experimental drug or device.
A Phase 4 trial takes place after the FDA approves the drug or device. The treatment’s effectiveness and safety are monitored in large, diverse populations. Sometimes, side effects may not become clear until more people have used the drug or device over a longer period of time.

Clinical trials that test a behavior change, rather than a drug or medical device, advance through similar steps, but behavioral interventions are not regulated by the FDA. Learn more about clinical trials , including the types of trials and the four phases.

Choosing to participate in research is an important personal decision. If you are considering joining a trial or study, get answers to your questions and know your options before you decide. Here are questions you might ask the research team when thinking about participating.

What is this study trying to find out?
What treatment or tests will I have? Will they hurt? Will you provide me with the test or lab results?
What are the chances I will be in the experimental group or the control group?
If the study tests a treatment, what are the possible risks, side effects, and benefits compared with my current treatment?
How long will the clinical trial last?
Where will the study take place? Will I need to stay in the hospital?
Will you provide a way for me to get to the study site if I need it, such as through a ride-share service?
Will I need a trial or study partner (for example, a family member or friend who knows me well) to come with me to the research site visits? If so, how long will he or she need to participate?
Can I participate in any part of the trial with my regular doctor or at a clinic closer to my home?
How will the study affect my everyday life?
What steps are being taken to ensure my privacy?
How will you protect my health while I participate?
What happens if my health problem gets worse during the trial or study?
Can I take my regular medicines while participating?
Who will be in charge of my care while I am in the trial or study? Will I be able to see my own doctors?
How will you keep my doctor informed about my participation?
If I withdraw from the trial or study, will this affect my normal care?
Will it cost me anything to be in the trial or study? If so, will I be reimbursed for expenses, such as travel, parking, lodging, or meals?
Will my insurance pay for costs not covered by the research, or must I pay out of pocket? If I don’t have insurance, am I still eligible to participate?
Will my trial or study partner be compensated for his or her time?
Will you follow up on my health after the end of the trial or study?
Will I continue receiving the treatment after the trial or study ends?
Will you tell me the results of the research?
Whom do I contact if I have questions after the trial or study ends?

Older man asking a researcher questions about clinical trials

To be eligible to participate, you may need to have certain characteristics, called inclusion criteria. For example, a clinical trial may need participants to have a certain stage of disease, version of a gene, or family history. Some trials require that participants have a study partner who can accompany them to clinic visits.

Participants with certain characteristics may not be allowed to participate in some trials. These characteristics are called exclusion criteria. They include factors such as specific health conditions or medications that could interfere with the treatment being tested.

Many volunteers must be screened to find enough people who are eligible for a trial or study. Generally, you can participate in only one clinical trial at a time, although this is not necessarily the case for observational studies. Different trials have different criteria, so being excluded from one trial does not necessarily mean you will be excluded from another.

Could You Make a Difference in Dementia Research? infographic

When research only includes people with similar backgrounds, the findings may not apply to or benefit a broader population. The results of clinical trials and studies with diverse participants may apply to more people. That’s why research benefits from having participants of different ages, sexes, races, and ethnicities.

Researchers need older adults to participate in clinical research so that scientists can learn more about how new drugs, tests, and other interventions will work for them. Many older adults have health needs that are different from those of younger people. For example, as people age, their bodies may react differently to certain drugs. Older adults may need different dosages of a drug to have the intended result. Also, some drugs may have different side effects in older people than in younger individuals. Having older adults enrolled in clinical trials and studies helps researchers get the information they need to develop the right treatments for this age group.

Researchers know that it may be challenging for some older adults to join a clinical trial or study. For example, if you have multiple health problems, can you participate in research that is looking at only one condition? If you are frail or have a disability, will you be strong enough to participate? If you no longer drive, how can you get to the research site? Talk to the research coordinator or staff about your concerns. The research team may have already thought about some of the potential obstacles and have a plan to make it easier for you to participate.

Read more about diversity in clinical trials .

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For more information about clinical trials.

Alzheimers.gov www.alzheimers.gov Explore the Alzheimers.gov website for information and resources on Alzheimer’s and related dementias from across the federal government.

Clinical Research Trials and You National Institutes of Health www.nih.gov/health-information/nih-clinical-research-trials-you

ClinicalTrials.gov www.clinicaltrials.gov

This content is provided by the NIH National Institute on Aging (NIA). NIA scientists and other experts review this content to ensure it is accurate and up to date.

Content reviewed: March 22, 2023

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An official website of the National Institutes of Health

Clinical Trials Versus Clinical Studies: What’s The Difference?

There are varying opinions on what constitutes a clinical study or a clinical trial. According to Good Clinical Practice (GCP) – specifically the ICH E6 guidelines – the terms clinical trial and clinical study can be used synonymously. GCP defines a clinical trial or study as:

“Any investigation in human subjects intended to discover or verify the clinical, pharmacological, and/or other pharmacodynamic effects of an investigational product(s), and/or to identify any adverse reactions to an investigational product(s), and/or to study absorption, distribution, metabolism, and excretion of an investigational product(s) with the object of ascertaining its safety and/or efficacy.”

Others distinguish between clinical studies and clinical trials. The National Institutes of Health (NIH), for example, describes two kinds of clinical study: “A clinical study involves research using human volunteers (also called participants) that is intended to add to medical knowledge. There are two main types of clinical studies: clinical trials (also called interventional studies) and observational studies.”

Observational Versus Interventional

These two main types of clinical study – observational and interventional – describe the approaches taken in each:

In observational studies, researchers observe study participants and record the effects of their current treatment without making any changes. Observational studies tend to be less involved for participants, who might need to complete questionnaires, for example. Participants will typically be people undergoing treatment for a medical condition, and the researchers will collect information about the results of that treatment without changing it or comparing the results to a control group.
In interventional studies – clinical trials – an intervention is tested in a group of participants, usually compared to a control group that does not receive the intervention but a placebo in its place. A clinical trial could be testing a potential drug, procedure or device. Clinical trials have evolved over hundreds of years and have a structured framework.

Medicine authorities like the Food and Drug Administration (FDA) in the US or the European Medicines Agency (EMA) in the EU require clinical trials proving the safety and efficacy of a drug before they will allow it on the market. They often then require the company or research institute that developed an approved drug to monitor its safety and efficacy over time through observational studies.

The Clinical Trial: An Important Clinical Research Study

The clinical trial is an intervention study – a specific type of clinical research study that aims to answer a defined question about a treatment. The treatment under investigation could be a new drug, medical device or behavior, for example. The question being posed is usually around the safety or efficacy of the intervention.

A clinical trial is preceded by a long process of preclinical research. First, the intervention is studied in the lab. These tests begin in vitro and often involve toxicity screening. Then they will progress to animals, such as mice or ferrets, for further toxicity and safety testing and to gather initial efficacy results. Animals are needed at this stage, as bodies are much more complex than pure tissues grown in the lab. It’s important to understand the impact of an intervention on various biological systems, such as the nervous and circulatory systems, before the drug is tested in patients.

If an intervention still appears promising after preclinical research, it will enter the five phases of a clinical trial:

Phase 0 – pharmacodynamics and pharmacokinetics trial on a small number of people
Phase I – safety trial on a small number of people
Phase II – efficacy trial with a control versus test group to determine dosage and efficacy
Phase III – safety and efficacy trial with a large number of people (usually over 1,000)
Phase IV – continuous monitoring through observation

Understanding Clinical Research

The distinction between types of clinical research study differs depending on who is defining them, and this is an important consideration for those undertaking clinical studies to take a treatment to market. For example, the NIH refers to interventional studies, while the FDA calls them clinical trials. This is the kind of information you can expect a CRO to know.

If you have specific questions about the research you want to undertake, or you’re looking for support with your trial, you can contact Siron Clinical .

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What is the Difference Between A Clinical Trial and A Clinical Study

People often use the terms "clinical trial" and "clinical study" interchangeably. Both fall under the umbrella term "clinical research," which is the study of health and illness in humans. This research involves people voluntarily participating under conditions set by the clinical researchers. If considering participating in clinical research , it's important to understand the differences between these terms.

What is a Clinical Study?

A clinical study is research using human participants to help experts learn about different medical conditions and treatments. There are two primary types of clinical studies: clinical trials and observational studies. Both are designed to help health care professionals expand their knowledge of viable treatment—or preventative—options for patients, including medications, medical devices, surgery techniques, and therapies (e.g. radiation). Clinical studies may also focus on the development of diagnostic tools to help detect or prevent diseases and other medical conditions.

Who Creates a Clinical Study?

Clinical studies are often sponsored by entities that pay for the research. Typical sponsors are academic medical centers, pharmaceutical companies, voluntary groups, and federal agencies, such as the National Institutes of Health (NIH), Department of Veterans Affairs (VA), and Department of Defense (DoD). Sponsors initiating clinical research want to learn more about medical conditions or identify viable treatments.

Who is in Charge of the Clinical Study?

Every study is led by a principal investigator, usually a medical doctor. It's common for studies to have research teams that include experts of varying degrees of expertise and experience. A clinical study team is often composed of doctors, nurses, social workers, and other types of healthcare professionals. Studies often take place in different facilities, including hospitals, community clinics, universities, or doctors' offices.

Can Anyone Join a Study?

When study parameters are built, the research team sets stringent protocols to help the study succeed. This determines eligibility criteria. Who can join will depend on if they meet established inclusion and exclusion criteria. Common criteria include:

Having specific illnesses or health conditions
Stage of a disease
Previous treatment history for a medical condition

Sometimes research teams choose individuals and ask them to participate if they meet predetermined eligibility factors.

What is a Clinical Trial?

A clinical trial is a component of a clinical study. People who participate in clinical trials are directed to follow the specific interventions set by the initial research protocols for the purpose of the study. Interventions may include drugs, devices, or modifications to a participants' behavior (e.g. diet and exercise). Sometimes it'll be a combination of one or more protocols.

What are Research Teams Looking for in Trials?

Trials are designed to help professionals gain insight and knowledge that will help identify effective new treatments or preventative strategies for medical conditions. The research team carefully tracks participants and how they react to the protocols within the study's parameters. To meet these goals, a clinical trial may:

Compare new with traditional, already-established medical treatments or interventions.
Compare two established medical treatments or interventions.
Compare a new drug treatment's effectiveness to a placebo (inert compound).

These are only a handful of techniques used. What the research teams establish depends upon the type of study and the outcome they're seeking (e.g. treatment for specific cancer types or medications to combat diseases) to determine safety and effectiveness.

How are Trials Conducted?

Trials are broken into four phases which are defined by the U.S. Food and Drug Administration (FDA) and established to help researchers find the right dosages, identify potential side effects, and, if all goes as hoped, gain FDA approval for clinical use. Each phase emphasizes a focus on safety and effectiveness.

Phase I clinical trials are experimental treatments, usually performed on a small group of (often) healthy people of a wide age range. This phase focuses on safety and side effects to determine correct uses or dosages.
Phase II clinical trials increase the number of participants (100 to 300), putting an emphasis on effectiveness and obtaining preliminary data to see if a drug (or device) works in people with certain diseases or conditions. Phase II can last years.
Phase III clinical trials increase participants further, frequently to thousands of participants. Researchers look at different populations and dosage amounts, along with using the treatment with other parameters (e.g. drug combinations). If Phase III succeeds, the FDA may approve the experimental drug or device for widespread use.
Phase IV clinical trials are the final stage where researchers monitor the drug or device's effectiveness and safety in large, diverse populations. Sometimes, side effects or other adverse reactions don't occur immediately, so safety is carefully monitored throughout Phase IV trials in patients that are receiving the new treatments in real-world settings.

People participate in clinical trials for many reasons. Some suffer from diseases where current treatment options don't work for them or there are no treatments at all. Healthy people participate to aid the development of new treatments or preventative measures.

How Can People Join Clinical Trials?

People who want to participate in clinical trials should first speak with their doctor. If their doctor agrees, they may be enrolled in a clinical trial through their medical office or be referred to another center. Other ways to join are to search for clinical trials or join clinicalconnection.com to receive notifications when new trials are available.

ClinicalConnection, founded by pharmaceutical research professionals, has been helping connect people with clinical trials since 2000.

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Clinical Trials

Observational studies, who conducts clinical studies, where are clinical studies conducted, how long do clinical studies last, reasons for conducting clinical studies, who can participate in a clinical study, how are participants protected, relationship to usual health care, considerations for participation, questions to ask, what is a clinical study.

A clinical study involves research using human volunteers (also called participants) that is intended to add to medical knowledge. There are two main types of clinical studies: clinical trials (also called interventional studies) and observational studies. ClinicalTrials.gov includes both interventional and observational studies.

In a clinical trial, participants receive specific interventions according to the research plan or protocol created by the investigators. These interventions may be medical products, such as drugs or devices; procedures; or changes to participants' behavior, such as diet. Clinical trials may compare a new medical approach to a standard one that is already available, to a placebo that contains no active ingredients, or to no intervention. Some clinical trials compare interventions that are already available to each other. When a new product or approach is being studied, it is not usually known whether it will be helpful, harmful, or no different than available alternatives (including no intervention). The investigators try to determine the safety and efficacy of the intervention by measuring certain outcomes in the participants. For example, investigators may give a drug or treatment to participants who have high blood pressure to see whether their blood pressure decreases.

Clinical trials used in drug development are sometimes described by phase. These phases are defined by the Food and Drug Administration (FDA).

Some people who are not eligible to participate in a clinical trial may be able to get experimental drugs or devices outside of a clinical trial through expanded access. See more information on expanded access from the FDA .

In an observational study, investigators assess health outcomes in groups of participants according to a research plan or protocol. Participants may receive interventions (which can include medical products such as drugs or devices) or procedures as part of their routine medical care, but participants are not assigned to specific interventions by the investigator (as in a clinical trial). For example, investigators may observe a group of older adults to learn more about the effects of different lifestyles on cardiac health.

Every clinical study is led by a principal investigator, who is often a medical doctor. Clinical studies also have a research team that may include doctors, nurses, social workers, and other health care professionals.

Clinical studies can be sponsored, or funded, by pharmaceutical companies, academic medical centers, voluntary groups, and other organizations, in addition to Federal agencies such as the National Institutes of Health, the U.S. Department of Defense, and the U.S. Department of Veterans Affairs. Doctors, other health care providers, and other individuals can also sponsor clinical research.

Clinical studies can take place in many locations, including hospitals, universities, doctors' offices, and community clinics. The location depends on who is conducting the study.

The length of a clinical study varies, depending on what is being studied. Participants are told how long the study will last before they enroll.

In general, clinical studies are designed to add to medical knowledge related to the treatment, diagnosis, and prevention of diseases or conditions. Some common reasons for conducting clinical studies include:

Evaluating one or more interventions (for example, drugs, medical devices, approaches to surgery or radiation therapy) for treating a disease, syndrome, or condition
Finding ways to prevent the initial development or recurrence of a disease or condition. These can include medicines, vaccines, or lifestyle changes, among other approaches.
Evaluating one or more interventions aimed at identifying or diagnosing a particular disease or condition
Examining methods for identifying a condition or the risk factors for that condition
Exploring and measuring ways to improve the comfort and quality of life through supportive care for people with a chronic illness

Participating in Clinical Studies

A clinical study is conducted according to a research plan known as the protocol. The protocol is designed to answer specific research questions and safeguard the health of participants. It contains the following information:

The reason for conducting the study
Who may participate in the study (the eligibility criteria)
The number of participants needed
The schedule of tests, procedures, or drugs and their dosages
The length of the study
What information will be gathered about the participants

Clinical studies have standards outlining who can participate. These standards are called eligibility criteria and are listed in the protocol. Some research studies seek participants who have the illnesses or conditions that will be studied, other studies are looking for healthy participants, and some studies are limited to a predetermined group of people who are asked by researchers to enroll.

Eligibility. The factors that allow someone to participate in a clinical study are called inclusion criteria, and the factors that disqualify someone from participating are called exclusion criteria. They are based on characteristics such as age, gender, the type and stage of a disease, previous treatment history, and other medical conditions.

Informed consent is a process used by researchers to provide potential and enrolled participants with information about a clinical study. This information helps people decide whether they want to enroll or continue to participate in the study. The informed consent process is intended to protect participants and should provide enough information for a person to understand the risks of, potential benefits of, and alternatives to the study. In addition to the informed consent document, the process may involve recruitment materials, verbal instructions, question-and-answer sessions, and activities to measure participant understanding. In general, a person must sign an informed consent document before joining a study to show that he or she was given information on the risks, potential benefits, and alternatives and that he or she understands it. Signing the document and providing consent is not a contract. Participants may withdraw from a study at any time, even if the study is not over. See the Questions to Ask section on this page for questions to ask a health care provider or researcher about participating in a clinical study.

Institutional review boards. Each federally supported or conducted clinical study and each study of a drug, biological product, or medical device regulated by FDA must be reviewed, approved, and monitored by an institutional review board (IRB). An IRB is made up of doctors, researchers, and members of the community. Its role is to make sure that the study is ethical and that the rights and welfare of participants are protected. This includes making sure that research risks are minimized and are reasonable in relation to any potential benefits, among other responsibilities. The IRB also reviews the informed consent document.

In addition to being monitored by an IRB, some clinical studies are also monitored by data monitoring committees (also called data safety and monitoring boards).

Various Federal agencies, including the Office of Human Subjects Research Protection and FDA, have the authority to determine whether sponsors of certain clinical studies are adequately protecting research participants.

Typically, participants continue to see their usual health care providers while enrolled in a clinical study. While most clinical studies provide participants with medical products or interventions related to the illness or condition being studied, they do not provide extended or complete health care. By having his or her usual health care provider work with the research team, a participant can make sure that the study protocol will not conflict with other medications or treatments that he or she receives.

Participating in a clinical study contributes to medical knowledge. The results of these studies can make a difference in the care of future patients by providing information about the benefits and risks of therapeutic, preventative, or diagnostic products or interventions.

Clinical trials provide the basis for the development and marketing of new drugs, biological products, and medical devices. Sometimes, the safety and the effectiveness of the experimental approach or use may not be fully known at the time of the trial. Some trials may provide participants with the prospect of receiving direct medical benefits, while others do not. Most trials involve some risk of harm or injury to the participant, although it may not be greater than the risks related to routine medical care or disease progression. (For trials approved by IRBs, the IRB has decided that the risks of participation have been minimized and are reasonable in relation to anticipated benefits.) Many trials require participants to undergo additional procedures, tests, and assessments based on the study protocol. These requirements will be described in the informed consent document. A potential participant should also discuss these issues with members of the research team and with his or her usual health care provider.

Anyone interested in participating in a clinical study should know as much as possible about the study and feel comfortable asking the research team questions about the study, the related procedures, and any expenses. The following questions may be helpful during such a discussion. Answers to some of these questions are provided in the informed consent document. Many of the questions are specific to clinical trials, but some also apply to observational studies.

What is being studied?
Why do researchers believe the intervention being tested might be effective? Why might it not be effective? Has it been tested before?
What are the possible interventions that I might receive during the trial?
How will it be determined which interventions I receive (for example, by chance)?
Who will know which intervention I receive during the trial? Will I know? Will members of the research team know?
How do the possible risks, side effects, and benefits of this trial compare with those of my current treatment?
What will I have to do?
What tests and procedures are involved?
How often will I have to visit the hospital or clinic?
Will hospitalization be required?
How long will the study last?
Who will pay for my participation?
Will I be reimbursed for other expenses?
What type of long-term follow-up care is part of this trial?
If I benefit from the intervention, will I be allowed to continue receiving it after the trial ends?
Will results of the study be provided to me?
Who will oversee my medical care while I am participating in the trial?
What are my options if I am injured during the study?
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Clinical Trials

About Clinical Studies

Research: it's all about patients.

Mayo's mission is about the patient, the patient comes first. So the mission and research here, is to advance how we can best help the patient, how to make sure the patient comes first in care. So in many ways, it's a cycle. It can start with as simple as an idea, worked on in a laboratory, brought to the patient bedside, and if everything goes right, and let's say it's helpful or beneficial, then brought on as a standard approach. And I think that is one of the unique characteristics of Mayo's approach to research, that patient-centeredness. That really helps to put it in its own spotlight.

At Mayo Clinic, the needs of the patient come first. Part of this commitment involves conducting medical research with the goal of helping patients live longer, healthier lives.

Through clinical studies, which involve people who volunteer to participate in them, researchers can better understand how to diagnose, treat and prevent diseases or conditions.

Types of clinical studies

Observational study. A type of study in which people are observed or certain outcomes are measured. No attempt is made by the researcher to affect the outcome — for example, no treatment is given by the researcher.
Clinical trial (interventional study). During clinical trials, researchers learn if a new test or treatment works and is safe. Treatments studied in clinical trials might be new drugs or new combinations of drugs, new surgical procedures or devices, or new ways to use existing treatments. Find out more about the five phases of non-cancer clinical trials on ClinicalTrials.gov or the National Cancer Institute phases of cancer trials .
Medical records research. Medical records research involves the use of information collected from medical records. By studying the medical records of large groups of people over long periods of time, researchers can see how diseases progress and which treatments and surgeries work best. Find out more about Minnesota research authorization .

Clinical studies may differ from standard medical care

A health care provider diagnoses and treats existing illnesses or conditions based on current clinical practice guidelines and available, approved treatments.

But researchers are constantly looking for new and better ways to prevent and treat disease. In their laboratories, they explore ideas and test hypotheses through discovery science. Some of these ideas move into formal clinical trials.

During clinical studies, researchers formally and scientifically gather new knowledge and possibly translate these findings into improved patient care.

Before clinical trials begin

This video demonstrates how discovery science works, what happens in the research lab before clinical studies begin, and how a discovery is transformed into a potential therapy ready to be tested in trials with human participants:

How clinical trials work

Trace the clinical trial journey from a discovery research idea to a viable translatable treatment for patients:

See a glossary of terms related to clinical studies, clinical trials and medical research on ClinicalTrials.gov.

Watch a video about clinical studies to help you prepare to participate.

Let's Talk About Clinical Research

Narrator: This presentation is a brief introduction to the terms, purposes, benefits and risks of clinical research.

If you have questions about the content of this program, talk with your health care provider.

What is clinical research?

Clinical research is a process to find new and better ways to understand, detect, control and treat health conditions. The scientific method is used to find answers to difficult health-related questions.

Ways to participate

There are many ways to participate in clinical research at Mayo Clinic. Three common ways are by volunteering to be in a study, by giving permission to have your medical record reviewed for research purposes, and by allowing your blood or tissue samples to be studied.

Types of clinical research

There are many types of clinical research:

Prevention studies look at ways to stop diseases from occurring or from recurring after successful treatment.
Screening studies compare detection methods for common conditions.
Diagnostic studies test methods for early identification of disease in those with symptoms.
Treatment studies test new combinations of drugs and new approaches to surgery, radiation therapy and complementary medicine.
The role of inheritance or genetic studies may be independent or part of other research.
Quality of life studies explore ways to manage symptoms of chronic illness or side effects of treatment.
Medical records studies review information from large groups of people.

Clinical research volunteers

Participants in clinical research volunteer to take part. Participants may be healthy, at high risk for developing a disease, or already diagnosed with a disease or illness. When a study is offered, individuals may choose whether or not to participate. If they choose to participate, they may leave the study at any time.

Research terms

You will hear many terms describing clinical research. These include research study, experiment, medical research and clinical trial.

Clinical trial

A clinical trial is research to answer specific questions about new therapies or new ways of using known treatments. Clinical trials take place in phases. For a treatment to become standard, it usually goes through two or three clinical trial phases. The early phases look at treatment safety. Later phases continue to look at safety and also determine the effectiveness of the treatment.

Phase I clinical trial

A small number of people participate in a phase I clinical trial. The goals are to determine safe dosages and methods of treatment delivery. This may be the first time the drug or intervention is used with people.

Phase II clinical trial

Phase II clinical trials have more participants. The goals are to evaluate the effectiveness of the treatment and to monitor side effects. Side effects are monitored in all the phases, but this is a special focus of phase II.

Phase III clinical trial

Phase III clinical trials have the largest number of participants and may take place in multiple health care centers. The goal of a phase III clinical trial is to compare the new treatment to the standard treatment. Sometimes the standard treatment is no treatment.

Phase IV clinical trial

A phase IV clinical trial may be conducted after U.S. Food and Drug Administration approval. The goal is to further assess the long-term safety and effectiveness of a therapy. Smaller numbers of participants may be enrolled if the disease is rare. Larger numbers will be enrolled for common diseases, such as diabetes or heart disease.

Clinical research sponsors

Mayo Clinic funds clinical research at facilities in Rochester, Minnesota; Jacksonville, Florida; and Arizona, and in the Mayo Clinic Health System. Clinical research is conducted in partnership with other medical centers throughout the world. Other sponsors of research at Mayo Clinic include the National Institutes of Health, device or pharmaceutical companies, foundations and organizations.

Clinical research at Mayo Clinic

Dr. Hugh Smith, former chair of Mayo Clinic Board of Governors, stated, "Our commitment to research is based on our knowledge that medicine must be constantly moving forward, that we need to continue our efforts to better understand disease and bring the latest medical knowledge to our practice and to our patients."

This fits with the term "translational research," meaning what is learned in the laboratory goes quickly to the patient's bedside and what is learned at the bedside is taken back to the laboratory.

Ethics and safety of clinical research

All clinical research conducted at Mayo Clinic is reviewed and approved by Mayo's Institutional Review Board. Multiple specialized committees and colleagues may also provide review of the research. Federal rules help ensure that clinical research is conducted in a safe and ethical manner.

Institutional review board

An institutional review board (IRB) reviews all clinical research proposals. The goal is to protect the welfare and safety of human subjects. The IRB continues its review as research is conducted.

Consent process

Participants sign a consent form to ensure that they understand key facts about a study. Such facts include that participation is voluntary and they may withdraw at any time. The consent form is an informational document, not a contract.

Study activities

Staff from the study team describe the research activities during the consent process. The research may include X-rays, blood tests, counseling or medications.

Study design

During the consent process, you may hear different phrases related to study design. Randomized means you will be assigned to a group by chance, much like a flip of a coin. In a single-blinded study, participants do not know which treatment they are receiving. In a double-blinded study, neither the participant nor the research team knows which treatment is being administered.

Some studies use an inactive substance called a placebo.

Multisite studies allow individuals from many different locations or health care centers to participate.

Remuneration

If the consent form states remuneration is provided, you will be paid for your time and participation in the study.

Some studies may involve additional cost. To address costs in a study, carefully review the consent form and discuss questions with the research team and your insurance company. Medicare may cover routine care costs that are part of clinical trials. Medicaid programs in some states may also provide routine care cost coverage, as well.

When considering participation in a research study, carefully look at the benefits and risks. Benefits may include earlier access to new clinical approaches and regular attention from a research team. Research participation often helps others in the future.

Risks/inconveniences

Risks may include side effects. The research treatment may be no better than the standard treatment. More visits, if required in the study, may be inconvenient.

Weigh your risks and benefits

Consider your situation as you weigh the risks and benefits of participation prior to enrolling and during the study. You may stop participation in the study at any time.

Ask questions

Stay informed while participating in research:

Write down questions you want answered.
If you do not understand, say so.
If you have concerns, speak up.

Website resources are available. The first website lists clinical research at Mayo Clinic. The second website, provided by the National Institutes of Health, lists studies occurring in the United States and throughout the world.

Additional information about clinical research may be found at the Mayo Clinic Barbara Woodward Lips Patient Education Center and the Stephen and Barbara Slaggie Family Cancer Education Center.

Clinical studies questions

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Email: [email protected]

Clinical Studies in Depth

Learning all you can about clinical studies helps you prepare to participate.

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Clinical Trials VS Clinical Studies – What’s The Difference?

Clinical trials and studies are sometimes used interchangeably but they are actually different subgroups of clinical research. A clinical trial is a part of a clinical study. Participants in studies and trials agree to participate under the scientists’ or doctors’ guidelines.

If you’re considering clinical research or participating in a clinical trial, it’s a good idea to know what you’re getting into. Let’s take a look at the different between clinical studies and clinical trials.

What is a Clinical Study?

Clinical studies assist researchers and clinicians in understanding medical conditions and treatments. Clinical trials and observational studies are the most popular forms of clinical studies. Both teach doctors and nurses about new pharmaceuticals, devices, surgical procedures, and therapies to treat or prevent patients’ ailments. They also develop diagnostic tools to detect and prevent diseases.

Who Conducts Clinical Studies?

Sponsors finance medical studies. Sponsors include university medical centers, pharmaceutical businesses, volunteers, and federal entities like the National Institutes of Health (NIH and the Department of Defense (DoD). Investors in clinical trials frequently seek new medical insights or possible remedies.

Who Leads a Clinical Study?

Doctors are the principal investigators or leaders of all research investigations. The lead investigator is the head of a research team and the team typically include professionals of varied skill levels like doctors, nurses, social workers, etc. The research is mainly done in hospitals, health facilities, or universities.

Can Anyone Participate in a Study?

The research team follows tight guidelines when setting study conditions. This assures success and that can determine who is allowed to participate in a study. Membership eligibility is based on predetermined criteria. Common factors include age, gender, ethnicity, presence of a certain disease, disease stage, and previous medical treatment.

Researchers occasionally randomly select people and ask them to participate if they meet particular requirements.

What’s a Clinical Trial?

Clinical trials are part of clinical studies. Participants must follow certain protocols and interventions of the clinical trial. Medicines, technologies, and behavioral changes are some of the interventions involved. Occasionally, a combination of intervention or protocols are used.

What Are Scientists Looking for in Clinical Trials?

Trials help doctors discover insights on new illness treatments and prevention methods. The study team meticulously records participant replies to study protocols. Clinical trials can:

Compare current and old medical procedures
Evaluate two well-established medical therapies and compare their results
Compare the effects of a new drug to those obtained using a placebo to determine its effectiveness

How Do Trials Work?

The FDA has a four-step clinical trial approach to help researchers find effective dosages, identify potential side effects, and, ideally, secure FDA approval for widespread clinical use. Each phase must focus on safety and effectiveness. The phases are:

Phase I clinical trials are small-scale experiments on healthy adults of diverse ages. This phase assesses the efficacy and side effects to determine the dose.
Phase II clinical trials involve 100–300 patients and is used to assess if a pharmaceutical or medical device is safe and effective for treating an illness or symptom.
Phase III clinical trials typically involve thousands of participants. Researchers analyze doses, populations, and other features. In Phase III, the FDA may approve an experimental drug or technology for widespread use.
Phase IV clinical trials are the final step in drug or device development. During Phase IV, the efficacy and safety in larger representative groups is evaluated. Due to the delayed onset of side effects and other adverse responses, Phase IV patients receiving the new medication or treatment in a real-world settings are carefully watched.

How to Participate in Clinical Trials

Before you enroll in a clinical trial, consult your doctor. They may need to provide permission for you to participate. Your doctor’s office may enroll patients in a clinical study or refer you to another center if your doctor gives permission. You can also search for a trial or join a free service that alerts you to new clinical trials.

If you’re interested in participating in a clinical trial, regularly check back on our website for all our volunteer opportunities. If you have any questions, please fill out our online contact form .

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Understanding Clinical Studies

Printable version

Part of the challenge of explaining clinical research to the public is describing the important points of a study without going into a detailed account of the study’s design. There are many different kinds of clinical studies, each with their own strengths and weaknesses, and no real shorthand way to explain them. Researchers sometimes don’t explicitly state the kind of study they’re talking about. To them, it’s obvious; they’ve been living and breathing this research for years, sometimes decades. But study design can often be difficult even for seasoned health and science communicators to understand.

The gold standard for proving that a treatment or medical approach works is a well-designed randomized controlled trial. This type of study allows researchers to test medical interventions by randomly assigning participants to treatment or control groups. The results can help determine if there’s a cause-and-effect relationship between the treatment and outcomes. But clinical researchers can’t always use this approach. For example, scientists can’t ethically study risky behaviors by asking people to start smoking or eating an unhealthy diet. And they can’t study the health effects of the environment by assigning people to live in different places.

Thus, researchers must often turn to some type of observational study, in which a population’s health or behaviors are observed and analyzed. These studies can’t prove cause and effect, but they can be useful for finding associations. Observational studies can also help researchers understand a situation and come up with hypotheses that can then be put to the test in clinical trials. These types of studies have been essential to understanding the genetic, infectious, environmental, and behavioral causes of disease.

We’ve developed a one-page guide to clarify the different kinds of clinical studies researchers use, to explain why researchers might use them, and to touch a little on each type’s strengths and weaknesses. We hope it can serve as a useful resource to explain clinical research, whether you’re describing the results of a study to the public or the design of a trial to a potential participant. Please take a look and share your thoughts with us by sending an email to [email protected] .

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Clinical Trials: What Patients Need to Know

Clinical Research Versus Medical Treatment

What is clinical research.

Clinical research refers to studies in which people participate as patients or healthy volunteers. Different terms are used to describe clinical research, including:

What is Clinical Research

Read the What is Clinical Research? text alternative

clinical studies

clinical trials

Clinical research may have a number of goals, such as:

developing new treatments or medications

identifying causes of illness

studying trends

evaluating ways in which genetics may be related to an illness.

The idea for a clinical research study—also known as a clinical trial—often starts in the laboratory. After researchers test new therapies or procedures in the laboratory and in animal studies, the most promising experimental treatments are moved into clinical trials, which are conducted in phases. During a trial, more information is gained about an experimental treatment, its risks, and its effectiveness.

Strict rules for clinical studies have been put in place by National Institutes of Health and the FDA. Some studies involve promising new treatments that may directly benefit participants. Others do not directly benefit participants, but may help scientists learn better ways to help people.

Confidentiality is an important part of clinical research and ensures that personal information is seen only by those authorized to have access. It also means that the personal identity and all medical information of clinical trial participants is known only to the individual patient and researchers. Results from a study will usually be presented only in terms of trends or overall findings and will not mention specific participants.

Clinical research is much different from the medical treatment you receive in a Healthcare Provider's office.

Who should consider clinical trials and why?

Some people participate in clinical trials because none of the standard (approved) treatment options have worked, or they are unable to tolerate certain side effects. Clinical trials provide another option when standard therapy has failed. Others participate in trials because they want to contribute to the advancement of medical knowledge.

All clinical trials have guidelines, called eligibility criteria, about who can participate. The criteria are based on such factors as age, sex, type and stage of disease, previous treatment history, and other medical conditions. This helps to reduce the variation within the study and to ensure that the researchers will be able to answer the questions they plan to study. Therefore, not everyone who applies for a clinical trial will be accepted.

It is important to test drugs and medical products in the people they are meant to help. It is also important to conduct research in a variety of people, because different people may respond differently to treatments. FDA seeks to ensure that people of different ages, races, ethnic groups, and genders are included in clinical trials. Learn more about FDA’s efforts to increase diversity in clinical trials .

Where are clinical trials conducted?

Clinical trials can be sponsored by organizations (such as a pharmaceutical company), Federal offices and agencies (such as the National Institutes of Health or the U.S. Department of Veterans Affairs), or individuals (such as doctors or health care providers). The sponsor determines the location(s) of the trials, which are usually conducted at universities, medical centers, clinics, hospitals, and other Federally or industry-funded research sites.

Are clinical trials safe?

FDA works to protect participants in clinical trials and to ensure that people have reliable information before deciding whether to join a clinical trial. The Federal government has regulations and guidelines for clinical research to protect participants from unreasonable risks. Although efforts are made to control the risks to participants, some may be unavoidable because we are still learning more about the medical treatments in the study.

The government requires researchers to give prospective participants complete and accurate information about what will happen during the trial. Before joining a particular study, you will be given an informed consent document that describes your rights as a participant, as well as details about the study, including potential risks. Signing it indicates that you understand that the trial is research and that you may leave at any time. The informed consent is part of the process that makes sure you understand the known risks associated with the study.

What should I think about before joining a clinical trial?

Before joining a clinical trial, it is important to learn as much as possible. Discuss your questions and concerns with members of the health care team conducting the trial. Also, discuss the trial with your health care provider to determine whether or not the trial is a good option based on your current treatment. Be sure you understand:

what happens during the trial

the type of health care you will receive

any related costs once you are enrolled in the trial

the benefits and risks associated with participating.

What is FDA’s role in approving new drugs and medical treatments?

FDA makes sure medical treatments are safe and effective for people to use. We do not develop new therapies or conduct clinical trials. Rather, we oversee the people who do. FDA staff meet with researchers and perform inspections of clinical trial study sites to protect the rights of patients and to verify the quality and integrity of the data.

Learn more about the Drug Development Process .

Where can I find clinical trials?

One good way to find out if there are any clinical trials that might help you is to ask your doctor. Other sources of information include:

FDA Clinical Trials Search . Search a database of Federally and privately supported studies available through clinicaltrials.gov. Learn about each trial’s purpose, who can participate, locations, and who to contact for more information.

Clinicaltrials.gov. Conduct more advanced searches

National Cancer Institute or call 1–800–4–CANCER (1–800–422–6237). Learn about clinical trials for people with cancer.

What is a placebo and how is it related to clinical trials?

A placebo is a pill, liquid, or powder that has no treatment value. It is often called a sugar pill. In clinical trials, experimental drugs are often compared with placebos to evaluate the treatment’s effectiveness.

Is there a chance I might get a placebo?

In clinical trials that include placebos, quite often neither patients nor their doctors know who is receiving the placebo and how is being treated with the experimental drug. Many cancer clinical trials, as well as trials for other serious and life-threatening conditions, do not include placebo control groups. In these cases, all participants receive the experimental drug. Ask the trial coordinator whether there is a chance you may get a placebo rather than the experimental drug. Then, talk with your doctor about what is best for you.

How do I find out what Phase a drug is in as part of the clinical trial?

Talk to the clinical trial coordinator to find out which phase the clinical trial is in. Learn more about the different clinical trial phases and whether they are right for you.

What happens to drugs that don't make it out of clinical trials?

Most drugs that undergo preclinical (animal) research never even make it to human testing and review by the FDA. The drug developers go back to begin the development process using what they learned during with their preclinical research. Learn more about drug development .

Learn more about the basics of clinical trial participation, read first hand experiences from actual clinical trial volunteers, and see explanations from researchers at the NIH Clinical Research Trials and You Web site.

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Types of clinical trials

Medical research studies involving people are called clinical trials.

There are two main types of trials or studies - interventional and observational.

Interventional trials aim to find out more about a particular intervention, or treatment. A computer puts people taking part into different treatment groups. This is so that the research team can compare the results.

Observational studies aim to find out what happens to people in different situations. The research team observe the people taking part, but they don’t influence what treatments people have. The people taking part aren’t put into treatment groups.

There are different types of trials within these two groups. This page has information about

Pilot studies and feasibility studies

Prevention trials, screening trials, treatment trials, multi-arm multi-stage (mams) trials, cohort studies.

Case control studies

Cross sectional studies

Pilot studies and feasibility studies are small versions of studies which are sometimes done before a large trial takes place.

Feasibility studies are designed to see if it is possible to do the main study. They aim to find out things such as whether patients and doctors are happy to take part, and how long it might take to collect and analyse the information. They don’t answer the main research question about how well a treatment works.

Pilot studies are small versions of the main study. Pilot studies help to test that all the main parts of the study work together. They may also help answer the research question. Sometimes the research team include the information collected during the pilot study in the results of the main study.

Prevention trials look at whether a particular treatment can help prevent cancer. The people taking part don't have cancer.

These trials can be for the general population or for people who have a higher than normal risk of developing a certain cancer. For example, this could include people with a strong family history of cancer.

Screening tests people for the early signs of cancer before they have any symptoms. As with prevention trials, screening trials can be for the general population. Or they can be for a group of people who have a higher than normal risk of developing a certain cancer.

Researchers may plan screening trials to see if new tests are reliable enough to detect particular types of cancer. Or they may try to find out if there is an overall benefit in picking up the cancer early.

For trials that compare two or more treatments, you are put into a treatment group at random. This is a randomised trial. They are the best way to get reliable information about how well a new treatment works. We have more information about randomisation .

A multi arm trial is a trial that has:

several treatment groups as well as

Multi-arm multi-stage (MAMS) trials have the same control group all the way through. The other treatment groups can change as the trial goes on. As these trials are more complex there are a number of treatments that people might have.

The research team may decide to stop recruiting people to a particular group. This could be because they have enough people to start looking at the results. Or because early results show the treatment isn’t working as well as they’d hoped.

The researchers may add new treatment groups as new drugs become available to look at. This means they don’t have to design and launch a brand new trial each time they want to research a new treatment. So it helps get results quicker.

The Stampede trial for prostate cancer is an example of a MAMS trial.

Observational studies Cohort studies, case control studies and cross sectional studies are all types of observational studies.

A cohort is a group of people, so cohort studies look at groups of people. A cohort study follows the group over a period of time.

A research team may recruit people who do not have cancer and collect information about them for a number of years. The researchers see who in the group develops cancer and who doesn’t. They then look to see whether the people who developed cancer had anything in common.

Cohort studies are very useful ways of finding out more about risk factors. But they are expensive and time consuming. They can be used when it wouldn’t be possible to test a theory any other way.

Case control studies

Case control studies work the opposite way to cohort studies. The research team recruits a group of people who have a disease (cases) and a group of people who don't (controls). They then look back to see how many people in each group were exposed to a certain risk factor.

Researchers want to make the results as reliable as possible. So they try to make sure the people in each group have the same general factors such as age or gender.

Case control studies are useful and they are quicker and cheaper than cohort studies. But the results may be less reliable. The research team often rely on people thinking back and remembering whether they were exposed to a certain risk factor or not. But people may not remember accurately, and this can affect the results.

Another issue is the difference between association and cause. Just because there is an association between a factor and a disease, it doesn’t mean that the factor causes the disease.

For example, a case control study may show that people with a lower income are more likely to develop cancer. But it doesn’t mean that the level of income itself causes cancer. It may mean that they have a poor diet or are more likely to smoke.

Cross sectional studies

Cross sectional studies are carried out at one point in time, or over a short period of time. They find out who has been exposed to a risk factor and who has developed cancer, and see if there is a link.

Cross sectional studies are quicker and cheaper to do. But the results can be less useful. Sometimes researchers do a cross sectional study first to find a possible link. Then they go on to do a case control or cohort study to look at the issue in more detail.

Oxford Handbook of Clinical and Healthcare Research (1st edition) R Sumantra, S Fitzpatrick, R Golubic and others Oxford University Press, 2016

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Difference between Clinical Trial and Clinical Study

Frequently asked questions.

Yes. The status of enrolment of the trial subjects shall be intimated to the CLA on quarterly basis or as appropriate as per the duration of treatment in accordance with the approved clinical trial protocol, whichever is earlier. Further, six monthly status report of each clinical trial, as to whether it is ongoing, completed or terminated, shall be submitted in SUGAM portal. In case of termination of any clinical trial the detailed reasons for such termination shall be communicated to CLA.

Medical devices |, current regulatory scenario for conducting medical device clinical trials in india · cliniexperts.

Current Regulatory Scenario for Conducting Medical Device Clinical Trials in India Medical devices complement the physician’s or surgeon’s expertise in examination, diagnosis, treatment, or follow-up. Access to medical devices helps a physician come up with the right diagnosis of the patient’s medical condition, or a surgeon to carry out a procedure accurately. These devices enjoy

Research Types Explained: Basic, Clinical, Translational

“Research” is a broad stroke of a word, the verbal equivalent of painting a wall instead of a masterpiece. There are important distinctions among the three principal types of medical research — basic, clinical and translational.

Whereas basic research is looking at questions related to how nature works, translational research aims to take what’s learned in basic research and apply that in the development of solutions to medical problems. Clinical research, then, takes those solutions and studies them in clinical trials. Together, they form a continuous research loop that transforms ideas into action in the form of new treatments and tests, and advances cutting-edge developments from the lab bench to the patient’s bedside and back again.

Basic Research

When it comes to science, the “basic” in basic research describes something that’s an essential starting point. “If you think of it in terms of construction, you can’t put up a beautiful, elegant house without first putting in a foundation,” says David Frank, MD , Associate Professor of Medicine, Medical Oncology, at Dana-Farber Cancer Institute. “In science, if you don’t first understand the basic research, then you can’t move on to advanced applications.”

Basic medical research is usually conducted by scientists with a PhD in such fields as biology and chemistry, among many others. They study the core building blocks of life — DNA, cells, proteins, molecules, etc. — to answer fundamental questions about their structures and how they work.

For example, oncologists now know that mutations in DNA enable the unchecked growth of cells in cancer. A scientist conducting basic research might ask: How does DNA work in a healthy cell? How do mutations occur? Where along the DNA sequence do mutations happen? And why?

“Basic research is fundamentally curiosity-driven research,” says Milka Kostic, Program Director, Chemical Biology at Dana-Farber Cancer Institute. “Think of that moment when an apple fell on Isaac Newton’s head. He thought to himself, ‘Why did that happen?’ and then went on to try to find the answer. That’s basic research.”

Dan Stover, MD, and Heather Parsons, MD, conduct basic research in metastatic breast cancer.

Clinical Research

Clinical research explores whether new treatments, medications and diagnostic techniques are safe and effective in patients. Physicians administer these to patients in rigorously controlled clinical trials, so that they can accurately and precisely monitor patients’ progress and evaluate the treatment’s efficacy, or measurable benefit.

“In clinical research, we’re trying to define the best treatment for a patient with a given condition,” Frank says. “We’re asking such questions as: Will this new treatment extend the life of a patient with a given type of cancer? Could this supportive medication diminish nausea, diarrhea or other side effects? Could this diagnostic test help physicians detect cancer earlier or distinguish between fast- and slow-growing cancers?”

Successful clinical researchers must draw on not only their medical training but also their knowledge of such areas as statistics, controls and regulatory compliance.

Translational Research

It’s neither practical nor safe to transition directly from studying individual cells to testing on patients. Translational research provides that crucial pivot point. It bridges the gap between basic and clinical research by bringing together a number of specialists to refine and advance the application of a discovery. “Biomedical science is so complex, and there’s so much knowledge available.” Frank says. “It’s through collaboration that advances are made.”

For example, let’s say a basic researcher has identified a gene that looks like a promising candidate for targeted therapy. Translational researchers would then evaluate thousands, if not millions, of potential compounds for the ideal combination that could be developed into a medicine to achieve the desired effect. They’d refine and test the compound on intermediate models, in laboratory and animal models. Then they would analyze those test results to determine proper dosage, side effects and other safety considerations before moving to first-in-human clinical trials. It’s the complex interplay of chemistry, biology, oncology, biostatistics, genomics, pharmacology and other specialties that makes such a translational study a success.

Collaboration and technology have been the twin drivers of recent quantum leaps in the quality and quantity of translational research. “Now, using modern molecular techniques,” Frank says, “we can learn so much from a tissue sample from a patient that we couldn’t before.”

Translational research provides a crucial pivot point after clinical trials as well. Investigators explore how the trial’s resulting treatment or guidelines can be implemented by physicians in their practice. And the clinical outcomes might also motivate basic researchers to reevaluate their original assumptions.

“Translational research is a two-way street,” Kostic says. “There is always conversation flowing in both directions. It’s a loop, a continuous cycle, with one research result inspiring another.”

Learn more about research at Dana-Farber .

Clinical Research vs Lab Research: An In-depth Analysis

Clinical research , a cornerstone in advancing patient care, involves human subjects to test the safety and effectiveness of new treatments , ranging from drugs to diagnostic tools. Unlike clinical research , laboratory research focuses on the foundational science behind medicine without direct human involvement , contributing significantly to medical lab science.

The contrast between clinical research vs lab research highlights the diverse approaches in the scientific pursuit of better healthcare, where every medical advancement once relied on volunteer participation in clinical studies 1 . Bridging these two fields promises to accelerate the translation of lab discoveries into practical medical applications, underscoring the importance of collaboration in future developments in medical lab science 1 2 .

The Evolution of Clinical Research

The evolution of clinical research traces its origins back to ancient times, with the world's first recorded clinical tria l found in the "Book of Daniel" where a dietary intervention was observed to improve health after 10 days. This historical milestone was followed by significant advancements including Avicenna's rules for drug testing in his ‘ Canon of Medicine’ and Ambroise Pare's accidental trial in 1537 , which introduced a novel therapy for wounded soldiers. The modern era of clinical trials was marked by James Lind's controlled trial on scurvy in 1747 , laying the foundational principles for contemporary clinical research methodologies. The progression from these early experiments to the structured, ethical, and scientifically rigorous trials of today highlights the dynamic nature of clinical research. This evolution was further shaped by the introduction of the placebo in the early 1800s and the establishment of ethical frameworks , starting with the Hippocratic Oath and later formalized by the Nuremberg Code in 1947 . The development of clinical research has been instrumental in advancing medical science, with each phase of clinical trials meticulously designed to ensure the safety and efficacy of new treatments for the benefit of patient care.

Key Components of Laboratory Research

Clinical Research Facility Sciences, pivotal in the realm of medical lab science, leverage laboratory data and services extensively for disease diagnosis, monitoring, and treatment 2 4 . These sciences are underpinned by professionals who, after obtaining a Bachelor's degree in fields such as clinical research facility science or biomedical sciences from NAACLS-accredited programs, perform crucial laboratory tests, analyze specimens, and furnish healthcare providers with critical insights into the results' significance and validity 2 . Notably, these activities are conducted in laboratory settings without involving human subjects, emphasizing the distinction between clinical and laboratory research 2 .

The infrastructure of laboratories is meticulously designed to support the complex and sensitive nature of laboratory tests and analyses. This includes sturdy tables and ample counter space for heavy equipment, overhead and adjustable shelving for efficient space utilization, and cabinets and drawers for organized storage. Additionally, the deployment of fume hoods, customized for specific research needs, is essential for the safe handling of chemicals. Compliance with safety regulations and proper storage of flammable items underscore the operational standards necessary for high-quality testing and analysis in medical breakthroughs 6 .

The scientific process in laboratory research unfolds through several key steps: hypothesis formulation, experiment design, data collection, data analysis, and report writing. This structured approach begins with formulating a tentative explanation for a phenomenon, followed by planning and conducting experiments using appropriate methods and tools. The subsequent collection and analysis of data facilitate testing the hypothesis, culminating in the documentation of the entire process and findings in a formal report or paper 7 . This systematic methodology underscores the rigorous and methodical nature of laboratory research, contributing significantly to advancements in medical lab science.

Bridging the Gap: Collaboration between Clinical and Laboratory Research

Bridging the gap between clinical and laboratory research involves fostering collaborative environments that leverage the strengths of both fields to advance medical science. Medical scientific studies bifurcate into clinical laboratory scientists, who interpret critical data for healthcare professionals, and clinical researchers, who lay the groundwork for medical education and understanding 4 . This collaboration is pivotal for both building the future of medicine and administering its current benefits 4 . Enhanced operational efficiency is achieved through cross-departmental synergy, reducing redundancies in resource and personnel utilization, and fostering faster adoption of best practices and innovations across the lab 8 . These collaborations are exemplified by real-world success stories from renowned institutions like Mayo Clinic and Stanford Health Care, which have demonstrated the profound impact of integrated efforts on medical advancements 8 .

Key strategies for effective collaboration include regular meetings to address challenges, the integration of digital communication platforms with lab databases for swift sharing of results, and the establishment of clear guidelines for consistency in sample collection and result dissemination 8 . Unified objectives ensure that despite methodological differences, the end goals of improving patient care and advancing medical knowledge remain aligned 8 . Furthermore, the adoption of cloud-based data systems and AI technologies not only facilitates seamless data sharing but also automates routine tasks, thereby enhancing productivity and enabling the discovery of new insights 9 .

Challenges such as competition, ethics reviews, insufficient research funds, and the recruitment of project managers underscore the complexities of collaborative efforts 9 . However, the benefits, including improved reputation, publication quality, knowledge transfer, and acceleration of the research process, often outweigh the costs and risks associated with collaboration 9 . Collaborative relationships in Translational Medical Research (TMR) among clinicians highlight a strong willingness to collaborate, with preferences varying across different stages of research and between preferring independent and interdependent relationships 9 . This willingness to collaborate is crucial for bridging the gap between clinical and laboratory research, ultimately leading to groundbreaking advancements in medical science.

Future Trends in Clinical and Laboratory Research

The future of clinical and laboratory research is poised for transformative changes, driven by technological advancements and evolving healthcare needs. Notably:

Greater Efficiency through Automation : The integration of automation in research processes promises to streamline workflows, reducing manual labor and enhancing precision 13 .

Collaboration and Capacity Sharing : Partnerships between research institutions will facilitate shared resources and expertise, optimizing research outputs 13 .

Remote Sample Support and Diagnostic Data Interoperability : These advancements will enable more inclusive research and improved patient care by allowing data to flow seamlessly between different healthcare systems 13 .

Artificial Intelligence and Machine Learning : AI and machine learning are set to revolutionize both clinical and laboratory research by providing advanced data analysis, predictive modeling, and personalized medicine approaches 13 14 .

Staffing Solutions and Digital Workflows : Addressing staffing shortages through innovative solutions, alongside the adoption of digital workflows, will be crucial for maintaining research momentum 14 .

New Diagnostic Technologies : The development of novel diagnostic methods and technologies, including next-generation sequencing and biomarker-based screenings, will enhance disease diagnosis and treatment 14 .

Regulatory Changes and Patient-Centric Approaches : Increased FDA oversight of laboratory-developed tests and a shift towards patient-centric research models will ensure safer and more effective healthcare solutions 14 16 .

Precision Medicine and Big Data Analytics : The focus on precision medicine, supported by real-world evidence and big data analytics, will tailor treatments to individual patient needs, improving outcomes 15 .

Decentralized Clinical Trials and Digital Health Technologies : The rise of decentralized trials and digital health tools, including remote monitoring, will make research more accessible and patient-friendly 15 .

Innovation in Testing and Consumer Health : Laboratories will explore new frontiers in diagnostics, such as multi-drug-of-abuse testing and T-cell testing, while also responding to consumer health trends with at-home testing services 14 18 .

These trends underscore a dynamic shift towards more efficient, patient-centered, and technologically advanced clinical and laboratory research, setting the stage for groundbreaking discoveries and innovations in healthcare 13 14 15 16 18 .

Through this detailed exploration, we have seen the distinct yet intertwined roles that clinical and laboratory research play in the advancement of medical science and patient care. By comparing their methodologies, evolution, and collaborative potential, it becomes clear that both domains are crucial for fostering innovations that can bridge the gap between theoretical knowledge and practical healthcare solutions. The synergy between clinical and laboratory research, as highlighted by various examples and future trend predictions, establishes an essential framework for the continual improvement of medical practices and patient outcomes.

As we look toward the future, the significance of embracing technological advancements, enhancing collaboration, and adopting patient-centric approaches cannot be overstressed. These elements are pivotal in navigating the challenges and leveraging the opportunities within clinical and laboratory research landscapes. The potential impacts of such advancements on the field of medicine and on societal health as a whole are immense, underscoring the imperative for ongoing research, dialogue, and innovation in bridging the gap between the laboratory bench and the patient's bedside.

What distinguishes clinical research from laboratory research? Clinical research involves studies that include human participants, aiming to understand health and illness and answer medical questions. Laboratory research, on the other hand, takes place in environments such as chemistry or biology labs, typically at colleges or medical schools, and does not involve human subjects. Instead, it focuses on experiments conducted on non-human samples or models.

How does a clinical laboratory differ from a research laboratory? Clinical laboratories are specialized facilities where laboratory information and services are utilized to diagnose, monitor, and treat diseases. Research laboratories, in contrast, are settings where scientific investigation is conducted to study illness and health in humans to answer medical and behavioral questions.

In what ways do clinical research and scientific research differ? Clinical research is a branch of medical research that directly applies knowledge to improve patient care, often through the study of human subjects. Scientific research, including basic science research, aims to understand the mechanisms of diseases and biological processes, which may not have immediate applications in patient care.

Can you outline the various types of medical research analysis? Medical research can be categorized into three primary types based on the study's nature: basic (experimental) research, clinical research, and epidemiological research. Clinical and epidemiological research can be further divided into interventional studies, which actively involve treating or intervening in the study subjects, and noninterventional studies, which observe outcomes without intervention.

Prevent CRA Fraud: 5 Strategies to Protect Your CRO Team

Everything you need to know about clinical research studies.

Clinical Trials vs. Clinical Research: What’s to Know?

“Wherever the art of medicine is loved, there is also a love of humanity” – Hippocrates

When new drugs, vaccines, and medical devices are developed and marketed, one of the most important things to address is safety—the tracking of adverse events related to the usage of medicinal products. But what goes on behind the scenes before a game-changing drug makes its market entry? The answer is clinical trials and clinical research. Let’s consider each of these activities

Clinical Trials

A clinical trial is a type of clinical research study. A clinical trial is an experiment designed to answer specific questions about possible new treatments or new ways of using existing (known) treatments. Clinical trials are done to determine whether new drugs or treatments are safe and effective. They are usually part of a long, careful process that may take many years to complete. Clinical trials are conducted in four phases:

Phase 1 – Tests carried out using an experimental drug or treatment on a small group, typically between 20 to 100 people, to evaluate the treatment for factors including identification of a safe dosage range, patient safety, and detection of side-effects.
Phase 2 – Experimental drug or treatment is given to a larger group of 100 to 300 people to evaluate its safety and to determine the drug’s efficacy.
Phase 3 – Testing of drug on a larger group of 300 to 3000 people to assess efficacy, effectiveness and safety.
Phase 4 – Post-marketing studies commence after treatment approvals by the approved regulatory body for drugs, e.g., the National Agency for Food and Drug Administration and Control (NAFDAC) in Nigeria and the Food and Drug Administration (FDA) in the US.

Clinical Research

Clinical research is the study of health and illness in people. It is a more encompassing discipline investigating how to prevent, diagnose and treat illness. Clinical research describes many different elements of scientific investigations. Simply put, it involves human participants and helps translate basic research carried out in laboratories into new information and treatments to benefit patients. There are different types of clinical research including treatment research, epidemiological studies, diagnostic research, and others.

Critical Contribution to Healthcare

Clinical research, therefore, includes the processes of clinical trials, epidemiological research, and health services. It also covers education, outcome management, and mental health services for participating individuals. These elements are all vital for medical innovation.

Clinical trials will not be a success without volunteers and participants. However, volunteers and participants must be informed of the risks and benefits of a successful clinical trial.

Volunteers who participate in these studies may benefit from accessing highly-effective treatments that could be deployed for debilitating illnesses. A volunteer can also gain full access to new medical treatments before they are widely available.

Without a doubt, the year 2020 presented many challenges to the healthcare industry–the COVID-19 pandemic ranking as the global antagonist. Those challenges are yet to be completely eliminated even in 2021, but they have brought endless opportunities to improve clinical trial processes across the world.

At Xcene Research, we continue to work at supporting clinical sites and sponsors in creating more efficient, decentralized processes with the patient always top of mind. Bringing care directly to patients is what we do best and we are excited to be part of this new frontier.

Children in covid-19 trials, the evolution of clinical trials, sickle cell disease management: past and future, 4 thoughts on “clinical trials vs. clinical research: what’s to know”.

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Choosing and evaluating randomisation methods in clinical trials: a qualitative study

Cydney L. Bruce ORCID: orcid.org/0000-0001-5448-4440 1 ,
Mais Iflaifel 1 ,
Alan Montgomery 1 ,
Reuben Ogollah 1 ,
Kirsty Sprange 1 &
Christopher Partlett 1

Trials volume 25 , Article number: 199 ( 2024 ) Cite this article

Metrics details

There exist many different methods of allocating participants to treatment groups during a randomised controlled trial. Although there is research that explores trial characteristics that are associated with the choice of method, there is still a lot of variety in practice not explained. This study used qualitative methods to explore more deeply the motivations behind researchers’ choice of randomisation, and which features of the method they use to evaluate the performance of these methods.

Data was collected from online focus groups with various stakeholders involved in the randomisation process. Focus groups were recorded and then transcribed verbatim. A thematic analysis was used to analyse the transcripts.

Twenty-five participants from twenty clinical trials units across the UK were recruited to take part in one of four focus groups. Four main themes were identified: how randomisation methods are selected; researchers’ opinions of the different methods; which features of the method are desirable and ways to measure method features.

Most researchers agree that the randomisation method should be selected based on key trial characteristics; however, for many, a unit standard is in place.

Opinions of methods were varied with some participants favouring stratified blocks and others favouring minimisation. This was generally due to researchers’ perception of the effect these methods had on balance and predictability.

Generally, predictability was considered more important than balance as adjustments cannot be made for it; however, most researchers felt that the importance of these two methods was dependent on the design of the study.

Balance is usually evaluated by tabulating variables by treatment arm and looking for perceived imbalances, predictability was generally considered much harder to measure, partly due to differing definitions.

There is a wide variety in practice on how randomisation methods are selected and researcher’s opinions on methods. The difference in practice observed when looking at randomisation method selection can be explained by a difference in unit practice, and also by a difference in researchers prioritisation of balance and predictability. The findings of this study show a need for more guidance on randomisation method selection.

Peer Review reports

Introduction

Randomisation is considered the gold standard for allocating interventions in clinical trials [ 1 ]. It allows researchers to control for selection bias, which can result in systematic differences in the characteristics of participants being compared in each treatment group. In addition, some allocation methods can be used to improve balance between randomised groups with respect to certain characteristics. There are various methods to achieve random allocations, each with different benefits and disadvantages [ 2 ].

Simple, or unrestricted, randomisation, for example, creates an entirely unpredictable sequence; however, this comes at the potential loss of balance of participant numbers and characteristics in each group. Restricted allocation methods, such as minimisation can ensure better balance with respect to key characteristics, but this comes at the cost of being more predictable [ 2 , 3 ].

The International Conference on Harmonization (ICH) E9 guideline “Statistical Principles for Clinical Trials” [ 4 ] developed by the European Medicines Agency (EMA) have given advice on randomisation selection as follows:

Unrestricted randomisation is an acceptable approach, but using blocks of an appropriate length has additional advantages.

Separate randomisation schemes should be used in multicentre trials. Stratification can also be valuable for important prognostic factors measured at baseline to promote balance. However, more than two or three stratification factors are rarely necessary.

Deterministic dynamic allocation methods should be avoided. They can be used with an appropriate random element and the potential impact on analysis should be considered.

There are some scenarios in which an allocation method may not be adequate. Simple randomisation can be susceptible to chronological bias and confounding, making the method potentially inadequate in small sample sizes with known confounders [ 5 ]. Permuted blocks have been shown to lead to more predictable sequences, even with varying block sizes, leaving the method susceptible to selection bias in unblinded studies [ 6 ]. Failure to select a randomisation method that is compatible with the trial design can lead to inefficiency or, worse, erode confidence in the trial conclusions.

Previous research shows there is little association between trial characteristics, other than the size of the trial, and choice of allocation method used in randomised trials [ 7 , 8 ]. How researchers choose how to allocate participants in randomised trials remains largely unexplained.

The aims of this research were twofold. The first was to investigate the motivations behind researchers' selection of randomisation methods, and the second was to identify the key features to consider when evaluating how different allocation methods perform.

Qualitative focus groups were facilitated by one researcher (CB) with support from two additional researchers (CP and RO). All three researchers have a statistical background. Two additional researchers (KS) and (MI) who have experience in qualitative methods were consulted on the design of the study and on the analysis method used.

Initially, four focus groups containing 4–8 researchers were planned, but it was decided that all interested participants would be included.

Recruitment

We aimed to recruit from three main stakeholder groups: Statisticians involved in the randomisation process, programmers who designed randomisation algorithms, and other members of clinical trials teams with experience of selecting allocation methods.

A sample of researchers from the above groups was recruited from the UK Clinical Research Collaboration (UKCRC) statistics, information systems and trial management working groups, and from the Trials Methodology Research Partnership (TMRP) statistical analysis and adaptive design working groups. The latter group was included with the aim of finding researchers experienced in less commonly used randomisation methods.

An invitation email was circulated via group membership lists containing a link to a short survey. This survey was used to collect contact information for interested researchers, as well as additional information on job role and any relevant additional experience such as having worked in the pharmaceutical industry or having been part of an oversight committee. Those who completed this survey were approached using a participant information sheet (Additional file 1 ). The survey data was used to create more balanced groups in terms of job role and level.

Data collection

The focus groups were conducted remotely using Microsoft Teams, with video and audio recordings, to be transcribed. At the beginning of each focus group consent of participants was verbally confirmed before recording began. A topic guide, developed and further revised following an initial pilot focus group, was used to shape the discussion. Following the pilot focus group, only small changes were made to the topic guide, hence it was felt the pilot focus group did not significantly differ from other groups and that the data collected was just as valid to the project as other focus groups. Participants were asked to draw on all previous experiences when considering the discussed topics.

The topic guide included five key sections (details of which are available in Additional file 2 ):

Randomisation method selection

Randomisation method opinions

Which method features are important?

Why are method features important?

How are method features measured/quantified?

When designing the topic guide for this study, definitions for the terms ‘balance’ and ‘predictability’ were presented to participants to ensure they used the same definitions consistently, and they were asked to consider these when responding to questions. These definitions are given in Table 1 .

During the focus groups those facilitating also used prompts in addition to the interview guide to encourage discussion or to follow-up on participant responses.

Automatic transcripts were produced directly from the video recording, which were reviewed and corrected by CB. All transcripts were then open coded by CB. The analysis included a deductive approach to identify themes based on the interview schedule topics as well as inductive to identify new emerging themes. Qualitative data management software, NVivo 12, was used to store and manage the data and categorise important themes from the data. A framework model was used to organise and chart the data [ 9 ]. This study followed the consolidated criteria for reporting qualitative research (COREQ) guidelines [ 10 ] (see Additional file 3 ). Transcripts are stored in a secure location with access only available to the study team. Quotes used have been anonymised.

Subthemes were identified from analysing the focus group transcripts that aligned with the 4 main questions presented to participants in the topic guide and are presented in the results.

Four focus groups were undertaken from May 2022 to June 2022. Thirty-one researchers responded to the initial recruitment email and were subsequently contacted with a follow-up invitation email, information sheet and consent form to take part in a focus group., Of those, 25 researchers from 20 different UK Clinical Trials Units (CTUs) responded and agreed to take part. The other 6 did not respond to the invitation email.

Focus groups were made up of 3 mixed groups, and 1 group containing only statisticians. Table 2 summarises the roles and CTUs in each of the focus groups.

Identified subthemes fall under the following 4 headings:

Question 1 — selection of randomisation method

Question 2 — participants opinions of the different randomisation methods

Question 3 — desirable features of a randomisation method

Question 4 — measuring/quantifying features of a randomisation method.

Where numbers of participants are provided in the findings these numbers do not represent a proportion of the total number of participants, they represent those participants only who expressed a particular view. Not all participants may have commented on every question.

Two main factors for selecting a randomisation method were identified, unit standard and trial design as shown in Table 3 . Ten participants (from 9 CTUs) discussed how their unit had a preferred method, sometimes due to implementation costs and unit expertise (further supporting quotation is listed in Additional file 4 : Table S1).

…the default position now in [unit] is minimisation and therefore you know, it’s almost like we justify not minimising … (Statistician 1).

Alternatively, those who did not report having a unit standard used the trial design to determine the method. The trial sample size and the number of variables used in the randomisation seemed to be the most important design features to consider. External influences were also attributed to informing this decision by 7 participants, listing the Medicines and Healthcare products Regulatory Agency (MHRA) and other regulatory bodies, the funders and publishers.

Now fifteen years ago, the European Medicines Agency was anti minimisation. (Statistician 11).

Aiming to comply with European Medicines Agency (EMA) guidance could lead researchers to avoid minimisation, whilst reviewers at the grant application stage may also affect the final choice of method, or randomisation variables included.

Some participants indicated that randomisation was outsourced to another company, whilst others indicated that their randomisation was performed in-house, which led to internal expertise playing a greater role in method selection.

When discussing who was involved in the selection process of randomisation methods, many participants indicated the need for more collaboration in teams; however, the statistician and chief investigator (CI) were named as being involved in the decision.

I’ve tried to engage other members of trial teams when designing trials so that designing randomisation is very much a multidisciplinary process (Statistician 2).

Finally, a few participants noted that their beliefs of how these methods should be selected did not always align with practice.

I would echo that disparity between what happens in practice and what happens in reality. (Statistician 2).

Some of the participants who stated that there was a unit standard did feel that more thought should be put into the selection process, but cited time, money, and expertise constraints as to why this did not happen.

Question 2 — participant opinions of the different randomisation methods

Most participants did not have strong opinions with respect to any of the randomisation methods, but instead, they felt that a good reason is needed to select any of the methods.

I don’t think a particular default position is healthy actually. I think you need good reasons for choosing either method. (Statistician 3).

The discussion predominantly covered three main randomisation methods; (i) simple, (ii) stratified block, and (iii) minimisation, and each of these are discussed in more detail in this section. A glossary of each of these terms is shown in Table 4 .

Simple randomisation

Although simple randomisation was widely accepted as an appropriate randomisation method for large sample sizes, very few researchers actually reported using this method, with many shying away, feeling that some form of restriction was needed to ensure some balance.

…that’s probably the reason why I’ve never used simple randomisation. I’d just being too worried that it might go adrift. (Statistician 4).

Multiple statisticians mentioned that although they felt the method was valid in studies with large sample sizes, other members of the trial team were not keen on a method that uses no restriction. Programmers commented that it was much more difficult to monitor the method.

Simple randomisation. It’s given me more sleepless nights than any other randomisation because we’ve had some horrendous balance. So one of the arms after 24 randomisations, 20, had gone into one arm, and you just if you were tossing a coin, you think there was something rather biased about it, and there’s no way to check. (Programmer 1).

Stratified blocks vs minimisation

In most cases, selection of a randomisation method was regarded as a choice between 2 methods: stratified block randomisation and minimisation, with few considering other methods beyond these.

Stratified blocks

Most participants agreed that stratified block randomisation is a valid and useful method of randomisation. Their views reflected the fact that blocks ensured balanced numbers in each group whilst strata can ensure balance with respect to a few characteristics; also, by using randomly permuted blocks, predictability can be greatly reduced.

The smaller the design, maybe you might consider minimisation, but generally for a reasonable size, go for stratified block randomisation. (Statistician 7).

Well, in terms of predictability, having more strata makes it harder for a site to be able to predict what’s coming next. Mixed block size is always help. If they don’t know how big the block is, they can’t see when the end’s coming. (Statistician 9).

Some participants however identified reservations around employing this method when there are a large number of strata. For example, including centre in the randomisation could lead to more imbalance as some blocks may never be completed.

…you can’t tell how the lists for the different stratification groups are going to get filled up so and with variable block sizes, you could, you know, quite unfortunately, go to a situation where you get actually a huge imbalance and that would be perfectly following the lists. (Programmer 1).

Others questioned the predictability of this method, especially when centre is included in the randomisation. When asked about when they would or would not feel comfortable to use this method, most participants agreed they would not include more than 3 variables with a small number of categories in stratified block randomisation.

Yeah, beyond three [stratification variables], I’d probably go for minimisation… (Statistician 9).

Minimisation

Most participants agreed that minimisation was most appropriate when a trial has ‘too many’ variables for stratified blocks or should be used with a small sample size. Those who favoured the method appreciated the ability to be able to include a multitude of factors as well as its perceived unpredictable nature in such situations.

If you’ve got a small number of 1 or 2 maybe 3 maximum binary factors that I think stratified probably takes it. If it's anything more than that, minimisation is probably essential… (Statistician 3).

However, those with reservations felt that the method could be overcomplicating the randomisation (allowing clinicians to list more prognostic values to balance on), and some expressed concerns over predictability.

I’ve had clinicians who want to balance on hundreds of factors because they think it may affect outcomes with or without treatment (Statistician 5).

Other methods

Most discussions focus on the main methods mentioned above, however, there was discussion of other methods.

Adaptive methods were discussed in three out of the four focus groups; however, some of our participants when asked were unaware of the methods and needed further details. Only one of the participants (statistician) had implemented these methods previously.

A lack of awareness may have contributed to their slow uptake. It was also discussed that another barrier is the fact that frequently used randomisation providers such as Sealed Envelope do not offer adaptive methods as standard. This means that to implement an adaptive method, researchers must either incur further costs for each alteration to the allocation ratio or design these methods in-house which can be very computationally intensive.

These barriers, rather than any fundamental opposition to the methodology, seemed to drive the lack of consideration given to these methods.

So why would you choose a design that leaves you with a lot of extra work on your back? That is not probably costed in any grant (Statistician 12).

Additionally, in one focus group, Atkinson’s method [ 11 ] was discussed as a better alternative to minimisation, however, it was also noted that this method requires full specification of the model beforehand, which can be very difficult to do.

Senn [Stephen Senn, Statistician] argues that you should use Atkinsons method, which requires you to know the model, so you have to fully specify the model before you start … you might not know all these things. (Statistician 3).

A model for method selection

By synthesising the general opinion of researchers, we have found a general method that participants who considered trial characteristics would follow, shown in Table 5 .

Question 3 — which features of a randomisation method are desirable

Balance vs unpredictability.

Discussion largely focussed on the trade-off between two desirable features of a randomisation method, balance and unpredictability. Although most participants stated that importance was dependent on the design of the trial, many when asked still indicated a preference. From Table 6 below, a clear preference for unpredictability can be seen. This is illustrated by comments made by multiple focus group members:

…there’s obviously ways for us to prepare analysis for imbalance, but it’s much harder to address the potential bias from the allocation concealment, or lack of, from predictability. (Statistician 6).

You’re trading off balance, which you can quantify against, for me, a far more important predictability which unless you go out and do field qualitative work, you will never find out. (Statistician 11).

A few focus group members discussed that imbalance can be handled in the analysis, which seemed to explain the elevated importance of achieving unpredictability. Instead, balance was considered a more practical issue, with the importance being more focused on balancing intervention delivery within recruiting sites, or considerations of safety outcomes. For example, by balancing on site, managing investigational medicinal product stock was easier as an equal number of each treatment could be delivered to each site. Balance in terms of participant characteristics also aided analysis/interpretation of safety data, which could not be dealt with in the analysis. Balance was considered a more important issue in trials with a lower number of participants.

…sometimes drug supply means that you’re forced to stratify by site, not through any particular biological reason or scientific reason, It’s just practicality. (Statistician 7).

Predictability was considered important to reduce risk of selection bias. Whilst many researchers felt that this issue was less important when trials were blinded, a small number of researchers did caution that a blinded trial did not always mean that predictability was protected and that clinicians may be aware of allocation even in a blinded trial due to effects of the treatment on participants or depletion of stock at sites.

so there is the potential for some predictability in that you may see the depletion of stock in that arm at a greater rate than the other arm. (Programmer 2).

There was also a discussion about how balance is often not done for statistical reasons as much as to appease other members of a trials team. Clinicians may feel uncomfortable not balancing on something, and a few participants discussed how balancing may be for publication, as publishers may be uncomfortable seeing a trial without some form of balancing.

I think often it makes clinicians feel more comfortable to balance on things. (Statistician 8).

The definition of predictability

An alternative definition for predictability was identified in the first focus group compared to the one we had presented in the topic guide. This definition centred around how often recruiters try to deliberately subvert randomisation (related quotes are presented in Additional file 4 : Table S3) and seemed to change participants’ view on the importance of predictability.

Participants that used our definition tended to consider predictability more important than those who defined predictability around how much recruiters are trying to subvert randomisation. This was due to a perceived lack of attempts to subvert randomisation.

…many of the trials I work in, which are often in like trauma situations or whatever; they don’t have time to guess what the next treatment is. (Statistician 8).

Other features

Three other logistical issues found to impact on the decision-making process are also presented in Table 7 .

Question 4 — how to measure/quantify features of a randomisation method

Participants discussed whether they measured and monitored the performance of randomisation methods, and if so, how they did it. Again, discussion largely focused on balance and predictability. Participants generally were comfortable with the idea of measuring and monitoring balance, while monitoring predictability was a much more challenging issue.

While many participants stated they did not directly check balance, researchers often confirm balance throughout the trial due to production of baseline characteristic tables in interim reports for the data monitoring committee. The baseline characteristics table allows researchers to confirm that there are similar numbers of participants per treatment group, and to check stratification or minimisation variables are balanced. One participant, however, discussed the difficulties of quantifying balance:

I think, balance might be the tougher one to quantify, because are you going to measure it on relative scales or absolute scales? Are you measuring differences? Are you measuring each variable in your table one in isolation, or are you assuming they’re correlated and looking at some multivariate measure? (Statistician 10).

Predictability

When discussing predictability, many participants stated that they did not measure the effect of predictability throughout the trial as this was too difficult to measure. Again, the differing definitions of predictability did bring different opinions here, with those using our definition (Table 1 ) suggesting the need to decide on rules that could reasonably be used by recruiters and testing how often a recruiter would be correct with this pattern.

…the horse I will back is the one that’s had the less allocations. So if you’ve seen seven of A and six of B, I’m accepting this only works if it’s open label, you will always get more than 50% accuracy by saying, well, the next one is more likely to be B. (Statistician 11).

Those whose definition of predictability hinged on how often researchers attempted to subvert the randomisation acknowledged that this would be very difficult to measure.

The aim of this study was to identify researcher motivations behind differences in practice in randomisation method selection, and to identify key method features that factor into these choices. This study found variation in practice, both between CTUs and sometimes within a CTU. Some CTUs had a clear method preference set as an institutional standard, at which point infrastructure built around this method can make using another method more difficult. Others decide the method based on trial design. In both cases, opinions on method performance came down to opinions of the importance of balance and predictability, and the perceived effect that each method had on these features.

Two main approaches were identified in focus groups which influenced methods selection, either a unit standard or based on the characteristics of the trial. A previous review [ 7 ], found that sample size and the number of centres seemed to be associated with choice of randomisation method, and this is in agreement with focus group findings.

However, many of the participants who stated they had a standard choice of method still acknowledged the importance of the trial design in how appropriate a randomisation method is. The general approach to method selection that seemed to be suggested by participants was in line with the EMA E9 guidance on randomisation method selection [ 4 ]. Considering that these views did not appear to reflect the participant’s practice, it is possible that researcher’s opinions come from knowing this guidance.

Within the literature, some researchers regard simple randomisation as the only true randomisation method and believe it should be more widely implemented [ 12 , 13 ] whilst others regard minimisation as the gold standard for obtaining balanced sequences [ 14 ].

Within our focus groups, whilst participants acknowledged the usefulness of simple randomisation, many did not use the method as they were concerned about the risk of imbalance. Even though studies showed that above a sample size of 200 these methods are valid and unlikely to experience issues with balance, [ 15 , 16 , 17 ] researchers in our groups were still reluctant to use these methods due to risk of imbalance, or perceived concerns from clinical staff.

Stratified randomisation, when considering the EMA’s guidance [ 4 ], is the preferred method, with the statement that more than two or three randomisation variables are usually not necessary. Focus group participants generally agreed up to three variables, but for more than this would use an alternative method such as minimisation.

There was a notable split in preferences between stratified block randomisation and minimisation relating to differing opinions of the effect methods had on balance and predictability. This suggests there is much needed research into the effect each of these methods has on predictability and balance measured in a multitude of ways in order to reassure researchers of the value of both methods and to hopefully lead researchers to the most efficient method based on the design on the trial.

Balance and predictability are long debated to be the two most important considerations when selecting a randomisation method [ 18 , 19 ]. Balanced groups can avoid issues in comparisons and make analysis easier, but come at the cost of more predictable sequences, which could lead to selection bias. The perceived importance of predictability was dependent on how researchers defined it.

The differing predictability definitions was a very unexpected outcome of the focus groups, being mentioned in 3 of 4 focus groups, suggesting a need for greater consideration on how both balance and predictability are defined and measured. Additional consideration should be given to logistical issues.

Although there is some research into methods to measure balance and predictability [ 20 , 21 , 22 ] this research does not appear to be used in practice among our study participants. Within focus groups, we found researchers had opinions on how methods would perform with respect to these features but did not implement any formal tests.

The differing definitions of predictability gave more context to the issues of measuring predictability. Participants who used our definition of predictability did have ways to measure this, although only theoretically. Those who felt that predictability should be defined by how often recruiters try to make these predictions felt that measuring this would be incredibly difficult, perhaps even impossible.

Previous research suggests that clinicians are not trying to subvert a randomisation sequence [ 18 ], suggesting less importance of predictability in this sense, the opinion of which was backed up by many of our focus group participants. However, this research relied on asking recruiters if they attempted to predict. When stating reasons recruiters did not try to predict allocations, one of these was that they were “aware this was wrong” which would suggest they may not want to answer this question honestly.

A case study previously looked at a trial where randomisation appeared to go wrong. Although they could not identify specific instances of misallocation, the study suggests inadequate allocation concealment did lead to allocation subversion [ 23 ] suggesting potentially a higher risk of subversion than reported.

Previous research in this area is however quite dated and it might be that understanding of the need for randomised trials and equipoise has increased, suggesting more research is needed to properly evaluate how often recruiters do attempt to subvert randomisations.

Strengths and limitations

This study benefits from having recruited researchers from a wide variety of institutions and with varying levels of experience and different roles. During recruitment, there was a push to include more members of trial management groups, but there was no additional uptake. Having only 1 participant who was not a statistician or programmer, this may reflect that these 2 roles play the biggest part in the randomisation method selection process and that other roles were unable to contribute to the group, rather than us missing a key stakeholder.

A limitation of this study is the fact that coding was only completed by one researcher, CB. We acknowledge that this does have the potential to introduce bias, however, feel that the effect would be limited. Focus groups were always attended by at least 2 researchers working on the project. During focus groups, we encouraged open and honest discussions, which is evidenced by the contrasting opinions presented in the data and in the analysis.

Conclusions

This study found there was a variation in practice in the selection and implementation of randomisation methodology. Whilst some researchers had preferences towards specific methods, many admitted that greater consideration should be given on how these methods are selected.

One of the biggest findings of note is that in many situations, the researcher’s views did not necessarily align with their current practice and many researchers had differing views of the of the effect methods had on balance and predictability. This highlights the need for greater investigation into randomisation method performance and the need for guidance to ease researchers when making these decisions.

Availability of data and materials

To protect the identity of focus group participants, source data is not available to request.

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Acknowledgements

We would like to thank all researchers who participated in the focus groups, as well as the Trials Methodology Research Partnership for their contribution towards this work.

This work is funded by the Nottingham Clinical Trials Unit (NCTU).

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CB, CP, RO and AM conceived the project with input from KS and MI to advise on qualitative methodology. CB, CP and RO facilitated the focus groups and were involved in data collection. CB coded the transcripts and analysed the data with guidance from KS and MI. CB drafted the manuscript, and all authors critically reviewed it and were involved in the interpretation of results.

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Correspondence to Cydney L. Bruce .

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No ethical approval was sought for this research as focus groups only contained researchers working in clinical trials units. A participant information sheet was included with the invitation for this study, and consent was verbally confirmed before focus group recording began.

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Additional file 1., additional file 2., additional file 3., additional file 4: table s1..

Quotes on institutional standards. Table S2. Additional study design features mentioned by researchers. Table S3. Quotes around the definition of predictability.

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Bruce, C.L., Iflaifel, M., Montgomery, A. et al. Choosing and evaluating randomisation methods in clinical trials: a qualitative study. Trials 25 , 199 (2024). https://doi.org/10.1186/s13063-024-08005-z

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Perspect Clin Res
v.9(4); Oct-Dec 2018

Study designs: Part 1 – An overview and classification

Priya ranganathan.

Department of Anaesthesiology, Tata Memorial Centre, Mumbai, Maharashtra, India

Rakesh Aggarwal

1 Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

There are several types of research study designs, each with its inherent strengths and flaws. The study design used to answer a particular research question depends on the nature of the question and the availability of resources. In this article, which is the first part of a series on “study designs,” we provide an overview of research study designs and their classification. The subsequent articles will focus on individual designs.

INTRODUCTION

Research study design is a framework, or the set of methods and procedures used to collect and analyze data on variables specified in a particular research problem.

Research study designs are of many types, each with its advantages and limitations. The type of study design used to answer a particular research question is determined by the nature of question, the goal of research, and the availability of resources. Since the design of a study can affect the validity of its results, it is important to understand the different types of study designs and their strengths and limitations.

There are some terms that are used frequently while classifying study designs which are described in the following sections.

A variable represents a measurable attribute that varies across study units, for example, individual participants in a study, or at times even when measured in an individual person over time. Some examples of variables include age, sex, weight, height, health status, alive/dead, diseased/healthy, annual income, smoking yes/no, and treated/untreated.

Exposure (or intervention) and outcome variables

A large proportion of research studies assess the relationship between two variables. Here, the question is whether one variable is associated with or responsible for change in the value of the other variable. Exposure (or intervention) refers to the risk factor whose effect is being studied. It is also referred to as the independent or the predictor variable. The outcome (or predicted or dependent) variable develops as a consequence of the exposure (or intervention). Typically, the term “exposure” is used when the “causative” variable is naturally determined (as in observational studies – examples include age, sex, smoking, and educational status), and the term “intervention” is preferred where the researcher assigns some or all participants to receive a particular treatment for the purpose of the study (experimental studies – e.g., administration of a drug). If a drug had been started in some individuals but not in the others, before the study started, this counts as exposure, and not as intervention – since the drug was not started specifically for the study.

Observational versus interventional (or experimental) studies

Observational studies are those where the researcher is documenting a naturally occurring relationship between the exposure and the outcome that he/she is studying. The researcher does not do any active intervention in any individual, and the exposure has already been decided naturally or by some other factor. For example, looking at the incidence of lung cancer in smokers versus nonsmokers, or comparing the antenatal dietary habits of mothers with normal and low-birth babies. In these studies, the investigator did not play any role in determining the smoking or dietary habit in individuals.

For an exposure to determine the outcome, it must precede the latter. Any variable that occurs simultaneously with or following the outcome cannot be causative, and hence is not considered as an “exposure.”

Observational studies can be either descriptive (nonanalytical) or analytical (inferential) – this is discussed later in this article.

Interventional studies are experiments where the researcher actively performs an intervention in some or all members of a group of participants. This intervention could take many forms – for example, administration of a drug or vaccine, performance of a diagnostic or therapeutic procedure, and introduction of an educational tool. For example, a study could randomly assign persons to receive aspirin or placebo for a specific duration and assess the effect on the risk of developing cerebrovascular events.

Descriptive versus analytical studies

Descriptive (or nonanalytical) studies, as the name suggests, merely try to describe the data on one or more characteristics of a group of individuals. These do not try to answer questions or establish relationships between variables. Examples of descriptive studies include case reports, case series, and cross-sectional surveys (please note that cross-sectional surveys may be analytical studies as well – this will be discussed in the next article in this series). Examples of descriptive studies include a survey of dietary habits among pregnant women or a case series of patients with an unusual reaction to a drug.

Analytical studies attempt to test a hypothesis and establish causal relationships between variables. In these studies, the researcher assesses the effect of an exposure (or intervention) on an outcome. As described earlier, analytical studies can be observational (if the exposure is naturally determined) or interventional (if the researcher actively administers the intervention).

Directionality of study designs

Based on the direction of inquiry, study designs may be classified as forward-direction or backward-direction. In forward-direction studies, the researcher starts with determining the exposure to a risk factor and then assesses whether the outcome occurs at a future time point. This design is known as a cohort study. For example, a researcher can follow a group of smokers and a group of nonsmokers to determine the incidence of lung cancer in each. In backward-direction studies, the researcher begins by determining whether the outcome is present (cases vs. noncases [also called controls]) and then traces the presence of prior exposure to a risk factor. These are known as case–control studies. For example, a researcher identifies a group of normal-weight babies and a group of low-birth weight babies and then asks the mothers about their dietary habits during the index pregnancy.

Prospective versus retrospective study designs

The terms “prospective” and “retrospective” refer to the timing of the research in relation to the development of the outcome. In retrospective studies, the outcome of interest has already occurred (or not occurred – e.g., in controls) in each individual by the time s/he is enrolled, and the data are collected either from records or by asking participants to recall exposures. There is no follow-up of participants. By contrast, in prospective studies, the outcome (and sometimes even the exposure or intervention) has not occurred when the study starts and participants are followed up over a period of time to determine the occurrence of outcomes. Typically, most cohort studies are prospective studies (though there may be retrospective cohorts), whereas case–control studies are retrospective studies. An interventional study has to be, by definition, a prospective study since the investigator determines the exposure for each study participant and then follows them to observe outcomes.

The terms “prospective” versus “retrospective” studies can be confusing. Let us think of an investigator who starts a case–control study. To him/her, the process of enrolling cases and controls over a period of several months appears prospective. Hence, the use of these terms is best avoided. Or, at the very least, one must be clear that the terms relate to work flow for each individual study participant, and not to the study as a whole.

Classification of study designs

Figure 1 depicts a simple classification of research study designs. The Centre for Evidence-based Medicine has put forward a useful three-point algorithm which can help determine the design of a research study from its methods section:[ 1 ]

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Object name is PCR-9-184-g001.jpg

Classification of research study designs

Does the study describe the characteristics of a sample or does it attempt to analyze (or draw inferences about) the relationship between two variables? – If no, then it is a descriptive study, and if yes, it is an analytical (inferential) study
If analytical, did the investigator determine the exposure? – If no, it is an observational study, and if yes, it is an experimental study
If observational, when was the outcome determined? – at the start of the study (case–control study), at the end of a period of follow-up (cohort study), or simultaneously (cross sectional).

In the next few pieces in the series, we will discuss various study designs in greater detail.

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Open access
Published: 20 March 2024

Accurate diagnosis and effective treatment of abnormal meridians in erectile dysfunction patients based on infrared thermography: an electrophysiological technique study

Zihao Wang ORCID: orcid.org/0000-0001-8015-818X 1 ,
Kaifeng Liu ORCID: orcid.org/0000-0003-3748-4080 1 , 2 , 3 , 4 ,
Shengmin Zhang 2 ,
Yongzhan Gong 3 &
Pengjie Lu 1

International Journal of Impotence Research ( 2024 ) Cite this article

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Metrics details

Clinical trials

Erectile dysfunction

An increasing body of research has demonstrated that appropriate stimulation of the meridians and acupoints in the human body can play a preventative and therapeutic role in diseases. This study combines the use of infrared thermography with intelligent electrophysiological diagnostic system (iEDS) to accurately diagnose and apply transdermal low-frequency electrical stimulation to treat abnormal meridians in patients with erectile dysfunction (ED). The treatment protocol included 6 treatments (each lasting 30 min and performed twice a week). The International Index of Erectile Function-5 (IIEF-5), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Erection Hardness Scale were used to assess treatment results. A total of 62 patients were included in this study, with 31 patients in the treatment group and 31 patients in the sham therapy group. After six treatments, the treatment group improved significantly in IIEF-5 (15.52 ± 2.06 vs. 18.84 ± 2.67, p < 0.001), PHQ-9 (8.32 ± 6.33 vs. 4.87 ± 4.41, p < 0.001), GAD-7 (5.32 ± 5.08 vs. 2.94 ± 3.31, p = 0.003), and EHS (2.48 (2.00, 3.00) vs. 2.90 (2.00, 3.00), p = 0.007). After six sham treatment sessions, no improvements in any of the scores were reported in the sham therapy group. Following that, this group had an additional six treatments of regular therapy, which resulted in statistically significant improvements in IIEF-5 (16.65 ± 1.96 VS. 19.16 ± 2.40 , p < 0.001), PHQ-9 (8.81 ± 6.25 VS. 4.97 ± 4.36, p < 0.001), GAD-7 (5.74 ± 5.18 VS. 3.68 ± 3.42, p < 0.001), and EHS (2.61 (2.00, 3.00) VS. 3.03 (2.00, 4.00), p = 0.003). No adverse events were reported regarding penile discomfort, pain, injury, or deformity.

The study protocol is registered in the Clinical Trials Registry with the identification number ChiCTR2300070262.

Radiofrequency energy in the treatment of erectile dysfunction—a novel cohort pilot study on safety, applicability, and short-term efficacy

Ilan Gruenwald, Boaz Appel, … Alexander Greenstein

Nocturnal penile tumescence devices: past, present and future

Jessica Nicole Schardein & Kelli Gross

The beginning of a new era: treatment of erectile dysfunction by use of physical energies as an alternative to pharmaceuticals

Ilan Gruenwald, Avner Spector, … Eitan Kimmel

Introduction

A great number of studies in recent years have shown that stimulating specific acupoints can effectively treat a wide range of disorders, including Parkinson’s disease [ 1 ], polycystic ovarian syndrome [ 2 ], knee osteoarthritis [ 3 ], and migraine [ 4 ]. In traditional Chinese medicine theory, there exists a mutual dependence between qi and blood. Qi is one of the fundamental substances that constitute and sustain human body and its life activities. It propels and regulates the vital functions of the human body. When the flow of Qi ceases within the body, it signifies the termination of life. Blood serves as the carrier of Qi, as Qi must rely on blood in order to ensure its proper functioning. Meridians and acupoints act as conduits for the flow, transit, and distribution of qi and blood throughout the body [ 5 ]. Preventive and therapeutic benefits in the treatment of associated disorders can be accomplished by correctly activating these pathways [ 6 ]. Acupoints can be stimulated with numerous types of energy, including mechanical stimulation by acupuncture and massage [ 7 ], heat stimulation by moxibustion [ 8 ], and electrical, magnetic, and laser stimulation. We used transcutaneous low-frequency electrical stimulation in concert with meridians and acupoints in our study to mimic the effects of acupuncture while avoiding the unpleasantness associated with needle insertion, such as pain and bleeding. This therapy achieves outcomes comparable to conventional acupuncture and electroacupuncture while displaying increased acceptance [ 9 ].

Meridians are an exceedingly ancient technique; however, nowadays, an increasing number of contemporary methodologies such as Laser Doppler blood flow monitoring, near infrared spectroscopy, and infrared thermography (IRT) are being applied in the study of meridians. IRT is the result of combining infrared energy camera technology with computer multimedia technology. The thermal field of the human body can be recorded with this imaging method. IRT provides visibility and non-invasiveness by dynamically detecting variations in body surface temperature. As a result, it is widely used in traditional Chinese medicine research [ 10 ].

Previous research on meridians employing IRT have generally focused on illness screening, detection, progression tracking, and therapy result verification [ 11 ]. However, there has been little in-depth study on illness diagnosis, particularly the identification and therapy of aberrant meridians in the human body. In this paper, we provide a unique method for combining infrared thermography with intelligent electrophysiological diagnostic system (iEDS). In this study, we utilized the theories of traditional chinese medicine on meridians to identify abnormal meridians in patients with erectile dysfunction (ED) through monitoring of target organs, target areas, and the overall condition. Additionally, we simultaneously determined the parameters for electro-physiological treatment. One of the most common male sexual dysfunctions is ED, which refers to the penis’s inability to generate or sustain a sufficiently hard erection for successful sexual intercourse [ 12 ]. It has a tremendous influence on the quality of life of both patients and their spouses, as well as the stability of their relationships [ 13 ]. Furthermore, ED serves as an early signal of a variety of chronic ailments, including cardiovascular/cerebrovascular diseases, metabolic abnormalities, and psychological issues [ 14 , 15 ]. phosphodiesterase type 5 (PDE5) inhibitors are the most often used therapeutic medicines for ED therapy [ 16 ]. However, study data show that PDE5 inhibitors are ineffective in roughly 35% of ED patients [ 17 ].

In this study, we used iEDS to administer electrical stimulation to ED patients with a variety of parameter settings. Concurrently, real-time infrared thermography was used to monitor and record temperature fluctuations in the target organ area. By comparing temperature changes of the target organ area, effective electrical stimulation parameters were determined. The goal of our study is to find the best electrical stimulation parameters and combinations for treating patients by comparing temperature changes in target organ areas before and after electrical stimulation with different parameters, and subsequently evaluate the therapeutic effects.

Materials and methods

Research objective.

The followings were the patients’ inclusion criteria: (1) Patients with IIEF-5 scores less than 22, (2) Patients who are in good physical condition, maintain regular daily routines, have a stable sexual partner, and can engage in normal sexual activity from the beginning to the end of the study, (3) Patients who have not taken any medication for ED in the 4 weeks prior to participating in this study and have not undergone any physical or surgical treatments for ED within the past 6 months, (4) Patients with normal results in their reproductive hormone tests. The followings were the patients’ exclusion criteria: (1) Patients with significant organic abnormalities affecting penile erection, (2) Patients with severe cardiovascular diseases that prevent sexual activity, (3) Patients who have undergone pacemaker surgery, (4) Patients with a history of neurological or psychiatric disorders, and (5) Patients with a history of substance abuse. Before the start of the study, patients completed IIEF-5, the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder-7 (GAD-7), and the Erection Hardness Score (EHS) under the guidance of physicians. These questionnaires were completed again during the follow-up visit two weeks after the completion of treatment. All participants in the study had previously signed informed consent forms. The research protocol has been registered with the Clinical Trial Registration Center under the identification code ChiCTR2300070262.

Preparation for inspection

The examination room is free of direct sunlight and air convection, and the temperature and humidity levels are carefully controlled at 22–26 °C and 40–60%, respectively. Patients must refrain from using vasodilating and vasoconstricting drugs for at least 24 h before the evaluation. Furthermore, patients should not eat or drink for at least 4 h before the test and should avoid being exposed to very hot or cold settings within 1 h before the evaluation. Patients should empty their bladders 15 min before the test, relax their belts, remove watches, necklaces, and other jewelry, and spend 10 min soothing themselves. They are allowed to stand or sit on a hard chair, but not on soft chairs such as couches.

Check for abnormal meridians

The patient undresses completely and places two electrodes on the Guanyuan (CV4) and Mingmen (GV4). Then, patient enter the medical infrared thermography inspection cabin. The patient is instructed to perform six movements (Fig. 1 ), with each movement being captured as a thermal image to serve as a baseline for infrared imaging photographs. The electrodes were linked to the BioStim pro (Foshan Shanshan Datang Medical Technology Co., Ltd., FoShan, China), and the 12 built-in electrical stimulation parameters were successively applied to the patient (Table 1 ). Each parameter was stimulated for 30 s, and an infrared thermographic picture was acquired to compare and evaluate with the baseline image (Fig. 2 ).

a Elevate the hands in close proximity to the ears, with palms oriented forward and all five fingers extended. b Position the hands on the head, tilting the head backwards to expose the neck. c Place the hands on the head and pivot 45° to the left. d Place the hands on the head and pivot 45° to the right. e Assume a stance with legs slightly apart, lowering the hands to the same width as the shoulders, with palms facing forward and all five fingers extended. f Maintain the fifth posture and rotate 180° in a backward direction.

Right: infrared images after treatment.

Determination of effective parameters and treatment

The value that caused a temperature shift more than 0.5 °C in the umbilicus area in the shortest amount of time was considered the effective parameter during the electrical stimulation procedure. After determining the appropriate parameters, the electrode pads are applied to the corresponding areas (Table 1 ) (The five most frequently observed abnormal meridians in our study, as well as the locations for electrode placement, are depicted in Fig. 3 ), and then connected to the BioStim ble6 (Foshan Shanshan Datang Medical Technology Co., Ltd., FoShan, China). Adjust the magnitude of the current to allow patients to perceive electrical stimulation without experiencing excessive pain. Each aberrant meridian was subjected to 30 min of electrical stimulation twice a week for a total of six therapy sessions.

KI Kidney Meridian, CV Conception vessel, GV Governor vessel, SP Spleen Meridian, SJ Sanjiao Meridian.

Between November 2022 and August 2023, A total of 62 patients with ED were included and evenly divided into two groups using complete random allocation. The group 1 (treatment group) had the detected aberrant meridians electrically stimulated. The group 2 (sham therapy group) got electrical stimulation treatments on normal upper limb meridians, which had no therapeutic impact on ED patients since they were normal meridians. After conducting the sham treatment, proceed with administering the standard treatment to the second group of patients. This study was a single-blind, randomized placebo-controlled trial. Patients remained unaware of their group assignment until the completion of the treatment.

Clinical outcome measurements

The IIEF-5 is a commonly employed questionnaire for assessing symptoms in individuals diagnosed with ED. The questionnaire has five questions, with four assessing the degree of erection and one assessing satisfaction with sexual intercourse. The total score ranges from 0 to 25, with a score below 22 indicating the presence of ED symptoms [ 18 , 19 ]. There is an interaction between ED and the psychological status of patients [ 20 ]. Research suggests that while psychological state may not be the direct cause of ED, it can potentially induce anxiety and depressive symptoms in patients [ 21 ]. We used PHQ-9 [ 22 , 23 ] and GAD-7 [ 24 , 25 ] to assess the patients’ psychological health. Furthermore, EHS [ 26 ] was used to quantify the quality of penile erection on a scale of 0 to 4.

Statistical methods

IBM SPSS Statistics 22.0(SPSS Inc., Chicago, IL, USA) was used for statistical analysis. The single-sample K-S test is employed to examine the normality of the data. Data exhibiting normal distribution is presented as mean ± standard error and is compared using paired-sample t -test；Data that does not conform to normal distribution is represented as median (first quartile, third quartile) and is compared using Wilcoxon signed-rank test. P < 0.05 was considered statistically significant.

Patient’s baseline

A total of 62 patients participated in our study, including 31 patients in the treatment group and 31 patients in the sham therapy group. Prior to treatment, there were no significant differences between the two groups in terms of age, BMI, IIEF-5, GAD-7, PHQ-9, and EHS (Table 2 ).

Post-treatment efficacy

In group 1 (treatment group), after receiving treatment, patients’ IIEF-5 scores improved from 15.52 ± 2.06 to 18.84 ± 2.67, p < 0.001. PHQ-9 scores decreased from 8.32 ± 6.33 to 4.87 ± 4.41, p < 0.001. GAD-7 scores decreased from 5.32 ± 5.08 to 2.94 ± 3.31, p = 0.003. EHS score improved from 2.48 (2.00, 3.00) to 2.90 (2.00, 3.00), p = 0.007 (Table 3 ). In group 2 (sham therapy group), there was no statistically significant improvement in any of the scores after sham treatment. After this, these patients underwent normal treatments and the patients’ IIEF-5 scores improved from 16.65 ± 1.96 to 19.16 ± 2.40, p < 0.001. PHQ-9 scores decreased from 8.81 ± 6.25 to 4.97 ± 4.36, p < 0.001. GAD-7 scores decreased from 5.74 ± 5.18 to 3.68 ± 3.42, p < 0.001. EHS score improved from 2.61 (2.00, 3.00) to 3.03 (2.00, 4.00), p = 0.003 (Table 4 ). During both the therapy phase and the follow-up period, no patients reported any penile discomfort, pain, damage, or deformity.

Low-frequency currents are pulsed currents with frequencies less than 1000 Hz in the medical profession, and low-frequency electrophysiology technology has found widespread application in clinical practice [ 27 ].The majority of biochemical activities in the human body involve the production and dissipation of heat, with heat loss largely occurring through cutaneous blood flow. When sickness develops, changes in general or local heat balance occur, resulting in temperature differences in the relevant locations. The importance of these variations in body surface temperature for illness diagnosis and therapy recommendations is now being investigated by researchers [ 28 ]. Notably, there is a connection between specific body parts’ surface temperatures with meridian channels, and acupoints, these places have greater temperatures than other areas [ 29 ]. The temperature of meridians shows whether the relevant functional areas are in a normal or pathological state [ 30 ]. Due to its sensitivity to infrared radiation and body surface temperature, IRT is a technology that is being used more and more in clinical research [ 31 ]. However, prior research has mostly focused on examining the connections between certain meridians and organs as well as making the distinction between meridian and non-meridian areas. Our study utilized IRT to visualize the data and combine them with the Chinese medicine meridian theory. We wanted to promote tailored diagnostic and treatment methods, ultimately resulting in increased clinical efficacy, by taking into account the diverse bodily constitution among individuals.

Bioelectrical signals are found throughout the human body’s physiological and pathological processes [ 32 ]. These electrical signals regulate several activities inside the organism, including the heart, skeletal muscles, skin, and neurological system. They are involved in functions such as heartbeat, bone regeneration, muscular contraction, wound healing, and neural transmission [ 33 ]. Electrical stimulations are critical to regulating cell proliferation, differentiation, adhesion, migration, and extracellular matrix production [ 34 ]. Electrical stimulation affects cellular depolarization, which has an effect on the organism. Low-frequency pulse currents of sufficient strength can create enough charge to activate neurons and cause an action potential. For cellular depolarization, different organs have set electrical stimulation parameters [ 35 ]. Despite the fact that the goal of treatment is the same, various tissue structures need varied electrical stimulation parameters [ 36 ]. The stimulation pulse width and waveform must also be addressed [ 37 ]. Our study’s goal was to place electrode patches to relevant acupoints of different meridians and use electrical stimulation parameters that corresponded to the meridians to get a batter therapeutic impact.

We placed electrode patches on the Guanyuan and Mingmen acupoints during the examination. First of all, the Spleen Meridian, Kidney Meridian, Liver Meridian, and Conception Vessel all converge in Guanyuan. Mingmen, an acupoint on the Governor Vessel, which is referred to as the “sea of yang qi” where all six yang meridians meet, is situated between the two kidneys. Second, both of these acupoints are situated in the lower dantian, which is shielded by adipose and muscular tissues and is far from the heart and brain. Therefore, we can effectively stimulate the meridians while reducing any discomfort that patients may feel by providing electrical stimulation with varying parameters. ED is known as “impotence” in traditional Chinese medicine. It refers to adult men’ failure to acquire or sustain a hard erection during sexual intercourse while not having reached the age-related loss in sexual function. Acupuncture treatment for ED focuses mostly on the Kidney Meridian, the Governor Vessel, the Spleen Meridian, and the Conception Vessel, which is consistent with our results. Furthermore, we discovered a considerable presence of the Sanjiao Meridian in the therapy of ED, which necessitates further in-depth investigation to explore its underlying causes.

Based on our previous experiences, most patients can accept non-pharmacological treatments to improve ED symptoms. However, frequent hospital visits and long waiting times for treatment are the main reasons for their treatment abandonment. In order to address these concerns, we have made improvements to the previous treatment approach. First, we accurately identify the abnormal meridians in patients. and then, simultaneous electrophysiological treatment is administered to all identified abnormal meridians, effectively reducing patient waiting and treatment times. Moreover, multiple courses of treatment can be provided to the patients.

However, our study does have some limitations. First, although we strictly adhered to the inclusion and exclusion criteria in patient selection, we did not exclude psychogenic erectile dysfunction (PED), which may have had a placebo effect on the results. Second, the skin temperature of the human body is influenced by physiological, pathological, and environmental factors. Physiological factors mainly include circadian rhythms [ 38 ], skin color [ 39 ], subcutaneous fat [ 40 ], and metabolic rate. Pathological factors primarily result from specific disease conditions. Environmental factors mainly encompass ambient temperature and relative humidity [ 41 ]. In this study, we rigorously controlled the room temperature and humidity, providing sufficient time for patients to acclimate to the environment. All these measures effectively reduced data inaccuracy and ensured the reliability of the results. However, both IRT and human body temperature are influenced by numerous factors. Although we have implemented various measures to control some of these factors, it is inevitable that other unknown factors may still introduce interference. In this study, although there was a statistically significant improvement in IIEF-5 score, the magnitude of improvement was not substantial. Therefore, further observation of the impact of multiple treatment courses on the improvement of ED symptoms will be conducted in our subsequent research.

There have been numerous discussions regarding the mechanisms by how electrical stimulation improves ED. The mainstream mechanisms include the improvement of corpus cavernosum smooth muscle structure, increased intracorneal pressure, promotion of endothelial cell release of nitric oxide (NO) [ 42 ], and facilitation of smooth muscle and neural regeneration within the corpus cavernosum [ 43 ]. In our study, each group was comprised of only 31 patients, and we just investigated the therapeutic effects of transcutaneous low-frequency electrical stimulation of meridians on ED. In the next step, we can continue to expand the sample size and incorporate combination therapy with medication to further explore the methods, mechanisms, and principles of using electrical stimulation through the meridians for the treatment of ED.

Conclusions

An increasing number of studies indicate that appropriate stimulation of the human meridians and acupoints can play a role in disease prevention and treatment. Our study entailed administering low-frequency electrical stimulation to patients with varying parameters, in conjunction with employing a medical infrared thermal imager to observe and record the patients’ surface temperature. By comparing the changes in temperature, it is possible to accurately identify abnormal meridians in the body and determine suitable treatment plans for the patients. The results demonstrate a significant improvement in the patients’ IIEF-5, PHQ-9, GAD-7, and ESH scores after treatment, providing evidence of the effectiveness of our intervention. Moving forward, our next steps will involve expanding the sample size and exploring the mechanisms of meridian therapy for treating ED.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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Acknowledgements

The study is supported by the Northern Jiangsu People’s Hospital of Jiangsu Province (NO.FCJS202354) and the Development Center for Medical Science & Technology National Health Commission of the People’s Republic of China research fund (NO.HDSL202001051).

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Conceived and/or designed the work that led to the submission, acquired data, and/or played an important role in interpreting the results: all authors. Drafted or revised the manuscript: ZW. Approved the final version: all authors. Agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved: KL.

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Zihao, W., Kaifeng, L., Shengmin, Z. et al. Accurate diagnosis and effective treatment of abnormal meridians in erectile dysfunction patients based on infrared thermography: an electrophysiological technique study. Int J Impot Res (2024). https://doi.org/10.1038/s41443-024-00859-w

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Synchronous versus metachronous spinal metastasis: a comparative study of survival outcomes following neurosurgical treatment

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Published: 19 March 2024
Volume 150 , article number 136 , ( 2024 )

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Mohammed Banat ORCID: orcid.org/0000-0001-7986-5215 1 ,
Anna-Laura Potthoff 1 ,
Motaz Hamed 1 ,
Valeri Borger 1 ,
Jasmin E. Scorzin 1 ,
Tim Lampmann 1 ,
Harun Asoglu 1 ,
Logman Khalafov 1 ,
Frederic C. Schmeel 2 ,
Daniel Paech 2 ,
Alexander Radbruch 2 ,
Louisa Nitsch 3 ,
Johannes Weller 3 ,
Ulrich Herrlinger 4 ,
Marieta Toma 5 ,
Gerrit H. Gielen 6 ,
Hartmut Vatter 1 &
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Patients with spinal metastases (SM) from solid neoplasms typically exhibit progression to an advanced cancer stage. Such metastases can either develop concurrently with an existing cancer diagnosis (termed metachronous SM) or emerge as the initial indication of an undiagnosed malignancy (referred to as synchronous SM). The present study investigates the prognostic implications of synchronous compared to metachronous SM following surgical resection.

From 2015 to 2020, a total of 211 individuals underwent surgical intervention for SM at our neuro-oncology facility. We conducted a survival analysis starting from the date of the neurosurgical procedure, comparing those diagnosed with synchronous SM against those with metachronous SM.

The predominant primary tumor types included lung cancer (23%), prostate cancer (21%), and breast cancer (11.3%). Of the participants, 97 (46%) had synchronous SM, while 114 (54%) had metachronous SM. The median overall survival post-surgery for those with synchronous SM was 13.5 months (95% confidence interval (CI) 6.1–15.8) compared to 13 months (95% CI 7.7–14.2) for those with metachronous SM ( p = 0.74).

Conclusions

Our findings suggest that the timing of SM diagnosis (synchronous versus metachronous) does not significantly affect survival outcomes following neurosurgical treatment for SM. These results support the consideration of neurosurgical procedures regardless of the temporal pattern of SM manifestation.

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Introduction

Systemic tumor disease with singular or multiple spinal metastases (SM) has assumed an increasingly prominent role in the daily clinical practice of spine surgeons and the lives of affected patients (Coleman 2006 ; Brande et al. 2022 ). It is estimated that approximately 5–15% of all cancer patients will ultimately develop spinal metastases (Brande et al. 2022 ; Jenis et al. 1999 ; Jacobs and Perrin 2001 ). Among the primary culprits are breast cancer, prostate cancer, and lung cancer, with the primary tumor remaining elusive in 3–10% of cases (Greenlee et al. 2000 ; Ulmar et al. 2007 ).

In the therapeutic arsenal for this profoundly affected patient population, surgery stands as a common treatment modality (Furlan et al. 2022 ). After lungs and liver, skeletal system and bones bear the brunt of systemic metastases (Macedo et al. 2017 ; Maccauro et al. 2011 ). Surgical options for managing spinal metastases encompass a spectrum, from biopsy coupled with vertebroplasty or kyphoplasty (Stangenberg et al. 2017 ; Georgy 2010 ), to spinal canal decompression in isolation (Patchell et al. 2005 ), or in conjunction with minimally invasive percutaneous procedures (Miscusi et al. 2015 ) and open instrumentation with augmented screws (Ringel et al. 2017 ; Park et al. 2019a ), at times necessitating anterior–posterior stabilization (Ulmar et al. 2006 ; Gezercan et al. 2016 ). The overarching objective of surgical intervention is the mitigation or prevention of neurological deficits, coupled with a focus on enhancing the patient’s quality of life (Fehlings et al. 2016 ; Depreitere et al. 2020 ). Additionally, surgery provides a means to attain a definitive histological diagnosis of the spinal tumor lesion and potentially improves overall survival (OS) (Patchell et al. 2005 ; Krober et al. 2004 ).

SM may arise within the context of a previously known and managed systemic cancer disease (metachronous presentation), often preceded by multimodal therapies, such as radiation, systemic chemotherapy, immunotherapy, or specifically targeted therapies (Gerszten et al. 2009 ; Berger 2008 ; Choi et al. 2015 , 2019 ). Alternatively, newly diagnosed SM may serve as the inaugural presentation of a previously undiscovered systemically disseminated cancer (synchronous presentation) (Jacobs and Perrin 2001 ; Bollen et al. 2018 ; Patnaik et al. 2020 ).

Despite existing literature, it remains uncertain whether the choice to surgically resect SM in cases of synchronous versus metachronous presentation significantly influences surgical decisions and patient survival. This study seeks to clarify this issue by examining the prognostic implications of synchronous versus metachronous SM diagnoses, measured from the day of neurosurgical SM resection, in patients who underwent surgical intervention for SM.

Patients and inclusion criteria

This study is based on consecutive patients aged >18 years who had undergone primary spinal canal decompression, with or without instrumentation, for SM between 2015 and 2020 at the neurosurgical department of the University Hospital Bonn. Comprehensive clinical data, including age, gender, primary tumor type, SM location, details of the neurosurgical procedure, the extent of spinal vertebrae involvement, American Society of Anesthesiologists (ASA) score, clinical-neurological assessment, and functional status measured by the American Spinal Injury Association (ASIA) Score ( 2019 ), were recorded.

Functional status was further evaluated using the Karnofsky Performance Scale (KPS) upon admission, categorizing patients into KPS ≥ 70% or KPS < 70%, as previously described (Schuss et al. 2021 ; Hamed et al. 2023 ; Schweppe et al. 2023 ; Ilic et al. 2021 ). The Charlson Comorbidity Index (CCI) was employed to quantify the comorbidity burden of patients before undergoing surgery (Hamed et al. 2022a ; Schneider et al. 2020 ; Lehmann et al. 2023 ).

Overall survival (OS) was calculated from the date of surgical SM resection until death as previously described (Hamed et al. 2022b ). Patients for whom no further follow-up information regarding survival was obtainable, typically due to ongoing treatment at external healthcare institutions, were excluded from subsequent statistical survival analysis.

Following histopathological analysis, all patients underwent thorough assessment by our internal Neurooncological Tumor Board, comprised of neurosurgeons, radiation therapists, neurooncologists, and neuroradiologist. Recommendations for post-surgery management were established through interdisciplinary consensus, occasionally coordinated with the treatment plans of referring physicians (Schafer et al. 2021 ).

Patients were categorized into two distinct cohorts for further analysis: those with SM diagnosed as a manifestation of a previously known cancer (metachronous presentation) and those with a new diagnosis of SM as the initial indication of an undiscovered cancer (synchronous presentation) (Potthoff et al. 2023 ).

Exclusion criteria encompassed patients classified as non-operable and those lacking complete data or follow-up information. Pertinent clinical parameters, including preoperative functional neurological status, comorbidities, radiological characteristics, primary cancer site, and the timing of diagnosis, were assessed for analysis.

The study adhered to the ethical principles outlined in the 1964 Helsinki Declaration and received approval from the Ethics Committee of the University Hospital Bonn (protocol no. 067/21). Given the retrospective nature of the study, the acquisition of informed consent from participants was not pursued.

Statistical analysis and graphical illustration

Data collection and analysis were conducted utilizing the SPSS computer software package for Windows (Version 27, IBM Corp., Armonk, NY). Categorical variables underwent analysis through contingency tables, employing the Fisher’s exact test when assessing two variables and the chi-square test when evaluating more than two variables. Non-normally distributed data were subjected to the Mann–Whitney U test. Overall survival (OS) rates were assessed using the Kaplan–Meier method, with Graph Pad Prism software for MacOS (Version 9.4.1, Graph pad Software, Inc., San Diego, California, USA) employed for this purpose. Survival rate comparisons were performed utilizing the Gehan–Breslow–Wilcoxon test. To identify predictors of elevated 1-year mortality, a multivariate logistic regression model was constructed using a backward stepwise approach. Statistical significance was determined at p < 0.05. Furthermore, the radar plot was generated using R (Version 3.6.2, Vienna, Austria), as previously outlined in reference (Lehmann et al. 2021 ).

Patient and tumor characteristics

Between 2015 and 2020, 211 patients had undergone resection of SM at the Neurosurgical Department of the University Hospital Bonn. The median patient age at the day of surgery was 66 years (interquartile range (IQR) 57–74 years) (Table 1 ). The most common primary tumor site was the lung (23%), followed by the prostate (22%) and the breast (11%). The thoracic spine was the most commonly affected segment of the spine with 56%. Single or dual-level disease was present in 126 patients (60%), whereas multilevel infiltration was present in 85 patients (40%). The majority of patients (62%) underwent decompression and dorsal stabilization, while spinal canal decompression alone was performed in 38% of the patients. Median CCI of the entire patient cohort was 8 (IQR 6–10). 67% of our cohort presented with a preoperative KPS score of ≥ 70. Median OS for the entire study cohort with surgically treated SM was 13 months (IQR 3–23).

79 of 211 of patients (46%) suffered from synchronous SM, 114 of 211 patients (54%) exhibited metachronous SM. For further more details of patient- and tumor-related characteristics, see Table 1 .

Survival rates do not significantly differ between synchronous and metachronous spinal metastases

In the synchronous SM group, 50 out of 93 patients (54%) succumbed within 1 year following surgical resection, compared to 60 out of 107 patients (56%) in the metachronous SM group ( p = 0.78) (Table 2 ). The mOS for patients with synchronous SM diagnosis was 13.5 months (95% CI 6.1–15.8), while patients with metachronous SM diagnosis exhibited a mOS of 13.0 months (95% CI 7.7–14.2) when calculated from the day of SM surgical treatment ( p = 0.74) (Fig. 1 ).

Kaplan–Meier survival analysis dependent on synchronous vs. metachronous SM occurrence. SM, spinal metastasis; vs., versus

Lung and breast carcinomas were significantly more common in the synchronous group, whereas prostate carcinoma was the most common tumor entity in the metachronous group (Table 2 ). The female gender was also significantly more frequently affected in the synchronous situation, with breast carcinoma being included. All the other parameters included in Table 2 did not significantly differ between the groups of synchronous and metachronous SM (Fig. 2 ; Table 2 ).

Radar plot depicting patient- and disease-related characteristics dependent on synchronous vs. metachronous SM occurrence in patients with surgically treated SM. CCI, Charlson comorbidity index; KPS, Karnofsky performance score; mOS, median overall survival; SM, spinal metastasis; vs., versus

Multivariable analysis for predictors of 1-year mortality

We performed a multivariable regression analysis including the variables sex, preoperative KPS, preoperative CCI, tumor entity, and time of diagnosis (synchronous versus (vs.) metachronous) in order to identify independent predictors of 1-year mortality following surgery for SM.

The multivariable analysis revealed preoperative KPS < 70 (OR 0.1, 95% CI 0.06–0.2, p < 0.001), preoperative CCI > 10 (OR 0.5, 95% CI 0.2–0.9, p < 0.001), and tumor entity breast (OR 0.2, 95% CI 0.07–0.7, p = 0.01) as significant and independent predictors of 1-year mortality (Table 3 ). Time of SM diagnosis (synchronous vs. metachronous SM presentation) did not meet statistical significance (OR 0.7, 95% CI 0.4–1.4, p = 0.3).

This study analyzes the prognostic impact of metachronous vs. synchronous SM diagnosis in patients who had undergone surgical therapy for SM. We found that the time of SM diagnosis does not impact 1-year mortality and patient survival when measured from the day of SM resection.

In the group of patients with SM from lung and breast cancer, SM significantly more often occurred in the synchronous than in the metachronous situation. Compared with this, SM from prostate and other carcinoma significantly more often occurred in the course of the known underlying cancer disease (metachronous situation). Lung cancer is notably associated with the highest incidence of spinal metastases (SM) and brain metastases (BM). The occurrence of SM in lung cancer patients, as reported in the literature, ranges from 5% to a significant 56%. This variation is influenced by factors, such as the histological type of the cancer, the status of the epidermal growth factor receptor (EGFR) mutation, and the stage of the disease (Berghoff et al. 2016 ; Nayak et al. 2012 ; Goncalves et al. 2016 ; Wang et al. 2017 ; Zhang et al. 2020 ; Rizzoli et al. 2013 ). Similarly, SM is observed in 5–15% of breast and prostate cancer cases, making these two types of cancer among the most common to develop SM (Rizzoli et al. 2013 ; Hong et al. 2020 ; Kumar et al. 2020 ; Park et al. 2019b ). The observed difference in the frequency of synchronous versus metachronous spinal metastasis (SM) diagnosis between lung and prostate cancer may be partially attributed to the diagnostic practices for these cancers. Prostate cancer may often be detected during routine medical check-ups for men, leading to earlier diagnosis. In contrast, lung cancer typically remains undetected until it reaches more advanced stages of the disease (Goldsmith 2014 ; Lux et al. 2019 ; Vinas et al. 2016 ).

Our findings regarding the distribution of cancer entities align with those reported in well-established studies (Krober et al. 2004 ; Hosono et al. 2005 ; Sciubba and Gokaslan 2006 ). Consistent with numerous publications, we observed that the thoracic spine was the most frequently affected spinal segment in both synchronous and metachronous SM groups (Bach et al. 1990 ; Comey et al. 1997 ). However, our study did not identify a specific dissemination pattern linked to the primary tumor, such as a preference for lung cancer metastases to manifest singularly or multiply in the thoracic spine, as noted in some reports (Schiff et al. 1998 ; Gilbert et al. 1978 ). Conversely, other researchers have observed a concentration of bronchial carcinoma in the thoracic spine and a predominance of prostate carcinoma in the lumbar spine (Krober et al. 2004 ).

In contemporary literature, the incidence of multiple spinal canal metastases in cases of spinal infiltration with SM is reported to be up to 30% (Sande et al. 1990 ). Our cohort demonstrates a prevalence with 45% in synchronous SM and 36% in metachronous SM involving more than three segments.

To the best of our knowledge, this study is the first to investigate the prognostic impact of synchronous versus metachronous SM. A notable aspect of our approach is the emphasis on postoperative survival in the survival analysis. This focus is crucial as it aligns with the typical juncture at which neurosurgeons encounter patients with spinal metastasis. These findings suggest that the indication for surgery should be considered regardless of whether the SM is synchronous or metachronous. This conclusion is significant for clinical decision-making in neurosurgery, suggesting that the timing of metastasis, in relation to the primary tumor, should not be a deterrent to surgical intervention.

In essence, our findings advocate for a surgical approach in managing spinal metastasis without bias toward the metastasis’ temporal classification. This has direct implications for neurosurgical management, underscoring the importance of considering surgery as a viable treatment option in both synchronous and metachronous scenarios and providing a clear directive for surgical intervention.

Limitations

This study is subject to a number of limitations. First, the data collection was retrospective in nature, and there was no randomization of patients; instead, treatment decisions were made based on the individual preferences of physicians at our institution. Additionally, the study population of patients with SM is notably diverse, encompassing a range of underlying cancer types and varying pre-treatment histories. Despite these limitations, our findings might provide a basis for the establishment of multicenter registries and the development of further prospective studies.

The present study indicates that the timing of SM diagnosis, whether synchronous or metachronous, does not substantially influence patient survival following surgical treatment. These findings imply that decisions regarding neurosurgical intervention should be considered independently of the temporal classification of SM.

Data availability

The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

Abbreviations

American Society of Anesthesiologists

American Spinal Injury Association

Charlson Comorbidity Index

Confidence interval

Karnofsky Performance Scale

Spinal metastases

Overall survival

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Department of Neuroradiology, University Hospital Bonn, Bonn, Germany

Frederic C. Schmeel, Daniel Paech & Alexander Radbruch

Department of Neurology, University Hospital Bonn, 53127, Bonn, Germany

Louisa Nitsch & Johannes Weller

Division of Clinical Neuro-Oncology, Department of Neurology, University Hospital Bonn, Bonn, Germany

Ulrich Herrlinger

Institute of Pathology, University Hospital Bonn, Bonn, Germany

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This manuscript has not been published or presented elsewhere in part or in entirety and is not under consideration by another journal. The study design was approved by the appropriate ethics review board. We have read and understood your journal’s policies, and we believe that neither the manuscript nor the study violates any of these. All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by MB, and MS. The first draft of the manuscript was written by MB and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

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Banat, M., Potthoff, AL., Hamed, M. et al. Synchronous versus metachronous spinal metastasis: a comparative study of survival outcomes following neurosurgical treatment. J Cancer Res Clin Oncol 150 , 136 (2024). https://doi.org/10.1007/s00432-024-05657-x

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Published: 16 March 2024

Satisfaction with clinical pathway implementation versus job performance of clinicians: empirical evidence on the mediating role of work engagement from public hospitals in Sichuan, China

Junlong Li 1 , 2 ,
Lu Ao 1 &
Jay Pan 1

BMC Health Services Research volume 24 , Article number: 348 ( 2024 ) Cite this article

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Metrics details

The job performance of clinicians is a clear indicator of both hospital capacity and the level of hospital service. It plays a crucial role in maintaining the effectiveness and quality of medical care. Clinical pathways are a systematic method of quality improvement successfully recommended by broader healthcare systems. Since clinicians play a key role in implementing clinical pathways in public hospitals, this study aims to investigate the effect of the satisfaction of clinicians in public hospitals with clinical pathway implementation on their job performance.

A cross-sectional study design was used. Questionnaires were administered online. A total of 794 clinicians completed the questionnaires in seven tertiary public hospitals in Sichuan Province, China, of which 723 were valid for analysis. Questionnaires contained questions on social demographic characteristics, satisfaction with clinical pathway implementation, work engagement, and job performance. Structural Equation Model (SEM) was used to test the hypotheses.

The satisfaction of clinicians in public hospitals with clinical pathway implementation was significantly positively correlated with work engagement ( r = 0.570, P < 0.01) and job performance ( r = 0.522, P < 0.01). A strong indirect effect of clinicians’ satisfaction with clinical pathway implementation on job performance mediated by work engagement was observed, and the value of this effect was 0.383 (boot 95%CI [0.323, 0.448]).

The satisfaction of clinicians in public hospitals with clinical pathway implementation not only directly influences their job performance, but also indirectly affects it through the mediating variable of work engagement. Therefore, managers of public hospitals need to pay close attention to clinicians’ evaluation and perception of the clinical pathway implementation. This entails taking adequate measures, such as providing strong organizational support and creating a favorable environment for the clinical pathway implementation. Additionally, focusing on teamwork to increase clinicians’ satisfaction can further enhance job performance. Furthermore, managers should give higher priority to increasing employees’ work engagement to improve clinicians’ job performance.

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Introduction

Job performance is an important concept in human resource management, which is the output of an organization’s activities to obtain the desired quantity, quality and efficiency of product or service [ 1 ]. The job performance of clinicians is their performance in the management of therapeutic treatment modalities and services offered by the hospital unit, which is an important manifestation of the capability and level of hospital service and is essential for the quality of medical services [ 2 , 3 ]. Currently, job performance is widely used to evaluate the competence of individual members of medical staff to make clinical diagnosis, administer treatment, and to assess their achievements and adherence to healthcare quality standards [ 4 ]. Research on the factors influencing the job performance of medical staff was done by both international and domestic scholars. While international studies highlight factors such as organizational support [ 5 , 6 ], teamwork [ 7 , 8 ], job satisfaction [ 9 ], work engagement, and role awareness [ 5 , 10 ], domestic research tends to emphasize psychological capital and work ability, as well as organizational commitment [ 11 , 12 , 13 ]. While existing research has made significant strides, much of the relevant literature predominantly examines healthcare systems in developed countries, with a particular emphasis on nurses. Studies addressing healthcare in developing countries, especially concerning doctors, are comparatively underrepresented in the literature [ 14 ]. Therefore, this study centers on clinicians in China and aims to provide academics with empirical evidence pertaining to the experiences of doctors in developing countries.

A clinical pathway is an interdisciplinary and integrated management model for clinical diagnosis and treatment, which is a standardized service plan for patients developed in a hospital by a group of multidisciplinary professionals for a particular disease. Its aim is to standardize procedures performed by medical staff, improve the quality and efficacy of medical services, and provide patients with better treatment [ 15 , 16 ]. Clinical pathways are now widely used in the global healthcare industry [ 17 ]. More than 80% of hospitals in the United States implemented them as early as in 2003, and most European countries are using them now [ 18 ]. By 2021, 91.3% of Chinese public hospitals at the secondary level and above had implemented clinical pathways [ 19 ]. Given that clinicians play a critical role in the implementation of clinical pathways, their satisfaction with this process has a significant impact on the application of clinical pathways and the effectiveness of medical quality management to a certain extent in Chinese public hospitals. Satisfaction among clinicians with the implementation of clinical pathways refers to their perceptions of organizational structure, assurance mechanisms, process operations, and outcome evaluations within the clinical pathway process. This satisfaction generally includes three dimensions: organizational support, process identification, and effect perception [ 20 ]. Li et al.‘s study demonstrated that the satisfaction of medical staff with clinical pathway implementation had a significant positive effect on the quality of healthcare services [ 21 ]. However, in reality, public hospital administrators pay more attention to patients’ attitudes and evaluation of the effects of implementing clinical pathways [ 22 , 23 ], while the attitudes and evaluations of doctors in this regard are usually overlooked. Hence, to enhance the quality of clinical pathway management in public hospitals, it is especially necessary to investigate doctors’ satisfaction with the implementation of clinical pathways and its impact on their work performance.

At present, there have been few studies exploring clinicians’ satisfaction with clinical pathway implementation [ 24 ], and even fewer examining the potential correlation between satisfaction and job performance. Recognizing the importance of this issue, the present study was designed and carried out to explore the relationship between satisfaction with clinical pathway implementation and job performance among Chinese clinicians.

Study framework and hypotheses

Previous studies have shown that employees’ job satisfaction is an important factor influencing job performance [ 25 , 26 ], but the mechanisms by which job satisfaction affects job performance are not yet well understood [ 27 ]. Job satisfaction is an individual’s positive subjective evaluation or attitude towards various aspects of work, which is influenced by many factors such as the job itself, job challenges, compensation system, interpersonal relationships, working conditions, work motivation, and organizational environment [ 28 , 29 , 30 ]. Clinicians’ job satisfaction is their positive evaluation or attitude towards various aspects of medical work in hospitals. Since the recent medical reform in China implements clinical pathways, they have become a substantial part of clinicians’ work which consists mainly of diagnosing and administering treatment. By the end of 2021, more than 1000 diseases had been included in clinical pathway management in China [ 20 ]. Therefore, clinicians’ satisfaction with clinical pathway implementation seems crucial in deriving job satisfaction.

Previous research points out that job satisfaction should be studied along with work engagement, as both concepts relate to individual motivation [ 31 ]. Work engagement is defined as a positive, affective-motivational state of work-related well-being, characterized by vitality, dedication and focus [ 32 , 33 ]. According to the job demand-resource model, job demands such as high workload, interpersonal conflicts, and unfavorable work environment may lead to dissatisfaction and burnout, and negatively affect the employee’s performance [ 34 ]. Job satisfaction generally includes satisfaction with nine aspects, i.e., pay, promotion opportunities, fringe benefits, rewards, supervision, interpersonal relationships, nature of work, communication, and working conditions [ 35 ]. The above nine aspects are on par with the satisfaction level of employees’ demands regarding their work environment. Consequently, high job satisfaction represents a high level of satisfaction with the work environment and other work demands, which can effectively motivate employees to work, and enhance their work engagement [ 36 ]. For example, to support the implementation of clinical pathways, clinicians need a robust electronic pathways system. A comprehensive electronic system better fulfills the conditions necessary for clinicians’ work, resulting in smoother workflow [ 37 , 38 , 39 ]. Consequently, the more motivated clinicians are to implement the clinical pathway, the degree of their engagement increases [ 37 , 38 , 39 ]. At the same time, employees with high work engagement have a strong sense of job identity and perform well at work [ 40 ].

In summary, we propose the use of the following hypotheses to determine the effect of satisfaction with clinical pathway implementation on job performance among clinicians in Chinese public hospitals.

Hypothesis 1

Clinicians’ satisfaction with clinical pathway implementation can positively influence job performance in public hospitals.

Hypothesis 2

Clinicians’ Satisfaction with clinical pathway implementation can positively influence work engagement in public hospitals.

Hypothesis 3

Work engagement plays a mediating role in the relationship between satisfaction with clinical pathway implementation and job performance among clinicians in public hospitals.

Study design and participants

A cross-sectional design was used to conduct a questionnaire survey of clinicians in seven tertiary public hospitals in Sichuan. Inclusion criteria: (1) being a licensed clinician; (2) working for more than 1 year; (3) participating in clinical pathway implementation and management. Exclusion criteria: physicians in hospital training, advanced training and internship. Benter and Chou indicated that the sample size should ideally be 10 times the number of items in the analysis [ 41 ]. For this study, a total of 61 items were included, comprising 21 items related to satisfaction with clinical pathway implementation, 16 on work engagement, 16 on job performance, and 8 covariates. Thus, the minimum sample size of 610 was considered sufficient to achieve good statistical power. Finally, a total of 794 clinicians completed the questionnaires, of which 723 evaluable questionnaires were recovered, representing an efficiency rate of 91.06%.

Data collection

Due to the COVID-19 pandemic restrictions and protocols, a field investigation was not conducted for this study. Data were collected using an online questionnaire tool, the Questionnaire Star website. The questionnaire link and QR code for the survey were distributed to clinicians working in various clinical departments with the assistance of the hospitals’ medical departments. The questionnaire consisted of a demographic information survey and three Chinese versions of maturation scales that had been validated in previous studies. Clinicians voluntarily participated in the survey after providing informed consent. The questionnaire was devised using appropriate Chinese language for clinicians, both in the questions and options, to increase the participation rates and improve the overall quality of the survey [ 42 ]. At the end of the survey, the questionnaire data were carefully reviewed and organized to remove incomplete questionnaires and outliers, to improve data representativeness.

Measurements

Demographic characteristics.

The demographic part of the questionnaire collected information on participants’ age, gender, marital status, education, income, professional title, length of service, and establishment status.

Satisfaction with clinical pathway implementation

This study adopted Satisfaction with Clinical Pathway Implementation Scale (SCPIS) developed by Li et al. [ 20 ] to assess clinicians’ satisfaction with clinical pathway implementation. The 21-item self-rating scale explored three dimensions: organizational support, process identity and perceived effectiveness. The relevant items in the questionnaire were structured in a Likert five-point format with 1 ~ 5 representing “very dissatisfied,” “slightly dissatisfied,” “uncertain,” “slightly satisfied,” and “very satisfied”, respectively. The items were scored positively, with higher scores indicating higher satisfaction levels. The minimum and maximum scores obtained from this scale were 21 and 105, respectively.

Work engagement

This study used the Work Engagement Scale (WES) revised by Li et al. [ 43 ] to assess clinicians’ work engagement. The 16-item self-rating scale explored three dimensions: vitality, dedication and concentration. The relevant items in the questionnaire were structured in a Likert seven-point scale ranging from “never” to “always”, and scores from 0 to 6, respectively. The items were scored positively, with higher scores indicating greater work engagement. The minimum and maximum scores obtained from this scale were 0 and 96, respectively.

Job performance

The Job Performance Scale (JPS) developed by Van Scotter et al. [ 44 ] was adopted for the study. The self-rating scale consists of 16 items, including three dimensions: work dedication, task performance and interpersonal facilitation. The scale used a Likert five-point format, with scores ranging from “very low” to “very high”, scored 1–5, respectively. The items were scored positively, with higher scores indicating greater job performance. The minimum and maximum scores obtained from this scale were 16 and 80, respectively.

Data analyses

IBM SPSS 26.0 and AMOS 25.0 were used to enter and analyze the data. P < 0.05 (two-tailed) was used to indicate statistical significance. Categorical data were described as frequency and constituent ratio (%), and total and item scores on each scale were represented as means (± standard deviations). Cronbach’s coefficient alpha and confirmatory factor analysis were used to assess the validity and reliability of the questionnaire. Single factor analyses of job performance were conducted using the independent-sample t-test and one-way ANOVA. Pearson correlation analysis was used to analyze the correlation between each variable. Structural Equation Model (SEM), using maximum likelihood estimation, was conducted to determine the influence of satisfaction with clinical pathway implementation and work engagement on job performance [ 45 ]. To control for potential confounding variables, the statistically significant variables in the univariate analysis (gender and marital status) were included as control variables in the regression models [ 46 , 47 ]. The fit indices of the models were evaluated using the following parameters: CMIN/df ≤ 5, root-mean-square error of approximation (RMSEA) ≤ 0.1, normed-fit index(NFI) ≥ 0.9, relative fit index (RFI) ≥ 0.9, comparative-fit-index (CFI) ≥ 0.9, goodness-of-fit index (GFI) ≥ 0.9 and parsimonious normal fit index (PNFI) ≥ 0.5 [ 48 , 49 , 50 , 51 , 52 ].

Patient and public involvement

Patients or the public were not involved in the design, conduct, reporting, or dissemination plans of this research.

Reliability and validity

The results of the reliability and validity analysis are shown in Table 1 . Cronbach’s alpha coefficients for all three scales and their dimensions were higher than 0.8. The composite reliability (CR) values of each dimension of the three scales were higher than 0.8. The average variance extracted (AVE) values for each dimension of the three scales were higher than 0.5. These results support the validity and reliability of the research instruments.

Participant characteristics

Table 2 shows descriptive characteristics of the participants ( n = 723). The participants included 393 males (54.36%) and 330 females (45.64%). The average age of participants was 35.37 ± 8.26 years.

Single factor analysis

The results are shown in Table 2 . Statistically significant differences were found in job performance based on gender ( P < 0.05) and marital status ( P < 0.05). However, differences in job performance based on age, educational status, work income, professional titles, work years, and establishment personnel status were not statistically significant ( P > 0.05).

Correlation analysis

According to the correlation analysis (Table 3 ), the results showed that satisfaction with clinical pathway implementation was significantly positively correlated to work engagement ( r = 0.570, p < 0.01) and job performance ( r = 0.522, p < 0.01). Besides, work engagement was significantly positively correlated to job performance ( r = 707, p < 0.01).

Mediation effect of work engagement

The study constructed a path diagram of a structural equation model of the satisfaction with clinical pathway implementation of clinicians in public hospitals as the independent variable work engagement as the mediating variable, and job performance as the dependent variable (Fig. 1 ). The model fitness fit indicators are shown in Table 4 . The results showed that the model fit indices GFI > 0.9, NFI > 0.9, RFI > 0.9, CFI > 0.9, PNFI > 0.5 and RMSEA < 0.1 all met the reference standard, while CMIN/df > 5, was slightly higher than the reference standard. According to Wen et al., the CMIN/df value is affected by the sample size, and when the sample size is large, it cannot be used as a criterion to assess whether the model fits the data [ 53 ]. This study included a large sample size, of 723, and therefore, CMIN/df can be excluded as one of the model’s fit test indices. Consequently, the model can be considered as fitting well the data.

The mediation model

Table 5 shows the results of the mediation effect analysis. As shown by the bias-corrected bootstrap, the boot 95% CI did not contain 0, indicating that the existence of the mediation effect was confirmed. Meanwhile, satisfaction with clinical pathway implementation had a significant positive effect on work engagement ( P < 0.001), work engagement significantly positively predicted job performance ( P < 0.001), and the direct effect of satisfaction with clinical pathway implementation on job performance was significant ( P < 0.001), indicating that work engagement had partial mediation effects between satisfaction with clinical pathway implementation and job performance. The value of this standardized mediation effect was 0.383 (boot 95%CI [0.323, 0.448]).

The results of the correlation analysis showed a significant correlation between satisfaction with clinical pathway implementation and job performance among clinicians in public hospitals, and that satisfaction with clinical pathway implementation had a positive effect on job performance, indicating that Hypothesis 1 has been confirmed. These results are consistent with findings from numerous studies examining the interrelation between job satisfaction and job performance. Specifically, Ekingen’s study on nurses [ 9 ], Hou et al.’s study on residents [ 54 ], and Liu et al.’s study on primary healthcare workers [ 55 ] provide concrete evidence of this relationship. While other studies focusing on the relationship between satisfaction with clinical pathway implementation and job performance have not been retrieved, the results of this study can be corroborated with the findings of Askari et al. Their research showed that clinical pathway software improved healthcare workers’ satisfaction and job performance [ 56 ]. According to Li et al., clinicians perceived their own satisfaction with clinical pathway implementation in three dimensions: satisfaction with organizational support, process identity, and perceived effectiveness during clinical pathway implementation [ 20 ]. Related studies have shown that a high level of organizational support leads to the perception of reciprocity [ 57 , 58 ]. When clinicians feel that the organization is willing and able to support them practically over the course of the implementation process, they, in return, will consciously engage in the behaviors expected by the hospital authorities, displaying more positive work attitudes and behaviors, thereby improving their job performance. As a standardized diagnosis and treatment mode, the standardized diagnosis and treatment implemented by a given clinical pathway are based on the guidelines developed by clinicians. As a result, effective cooperation within the department, also between the medical and nursing staff has a crucial role in implementing this clinical pathway. If clinicians show a low level of satisfaction with the programs and operating mechanisms during the implementation of a clinical pathway, it indicates that the implementation is challenging for them. Such a perception will inevitably reduce the efficiency of their work and negatively affect job performance. According to the social exchange theory and the principle of reciprocity [ 59 ], when an individual perceives that their effort is not proportional to the reward, this individual’s motivation to work will decrease, thereby reducing their job performance. A clinical pathway, as an important means to standardize clinicians’ responsibilities regarding giving diagnosis and administering treatment and to reduce patients’ medical costs, decreases, to a certain extent, the clinicians’ autonomy. Benefits from a clinical pathway for clinicians may include comparatively greater work efficiency, economic returns, quality of medical services or doctor-patient relationship after the implementation. If the clinicians’ perception of the benefits of the clinical pathway does not outweigh the effort required to implement it, their motivation and enthusiasm will decrease, and thereby their job performance. As a result when the clinicians’ perception of the clinicians’ a high level of satisfaction with clinical pathway implementation has, therefore, a positive effect on the job performance of clinicians in public hospitals.

Our findings show that work engagement has a partial mediating effect on the relationship between clinicians’ satisfaction with clinical pathway implementation and job performance in public hospitals. Namely, clinicians’ satisfaction with clinical pathway implementation not only directly, but also indirectly affects the job performance through the engagement in work, indicating that Hypothesis 2 and Hypothesis 3 have been confirmed. These hypotheses are backed by evidence from multiple studies. For instance, González-Gancedo et al. found a significant positive correlation between job satisfaction and work engagement among nurses [ 60 ]. Additionally, Bernales-Turpo et al. [ 61 ] and Zhang et al. [ 62 ] demonstrated in their research on medical staff that work engagement can function as a mediating variable for job performance and its predictors. Job satisfaction influences work engagement, which in turn is associated with higher job performance [ 63 ]. According to the job-demand resource theory, the factors affecting work engagement include both work demand and work resources, and if an individual’s work resources are continuously depleted and not replenished in a timely manner, their motivation for work and work engagement will be reduced [ 34 , 64 , 65 ]. Clinicians’ satisfaction with clinical pathway implementation is essentially their perception of organizational support, operating mechanisms, teamwork, and work effects during the clinical pathway implementation, which is an important component of clinicians’ work resources [ 66 ]. Such as when clinicians are unsatisfied with the implementation of clinical pathway, which means that benefits from the implementation of clinical pathway are smaller than the continuous input, their work motivation will decrease, which in turn will reduce their work engagement (i.e. they will devote less energy, focus and dedication to their work) [ 67 ]. Eventually, this will result in a reduction of in clinicians’ effectiveness and job performance. Taking into consideration the above, high levels of satisfaction of clinicians can help them engage more in work during implementing clinical pathways, which in turn will increase their job performance and ensure high standards of medical care.

Limitations and recommendations

There are some limitations in this study that need to be noted for improvement in future research. First, this study is cross-sectional design. The data comes only from one point in time, which does not reflect the change of relevant variables over time nor causal relationship. Second, the sample of this study was only from one province in western China, which decreases the representativeness of the sample. Third, the data for the study came from participants’ self-reports that may be affected by social desirability bias. Lastly, our analysis focused solely on the overall relationship between clinicians’ satisfaction with clinical pathway implementation and job performance. In this study, we did not consider that there may be differences in clinicians’ satisfaction with clinical pathway implementation and job performance,.in the face of different pathway types and pathway implementation time. Acknowledging these four limitations, future studies may consider the following: (a) adopting a longitudinal design to test the causal relationship between the study variables; (b) using a larger sample to improve the representativeness of the data; (c) using more objective indicators to reduce data bias; and (d) taking into account different types of pathways and different implementation times to make the study more in-depth.

To the best of our knowledge, this is the first study to offer empirical evidence on the impact of satisfaction of clinicians in public hospitals with clinical pathway implementation on their job performance. We confirmed that clinicians’ satisfaction with clinical pathway implementation in public hospitals has a direct positive effect on job performance, and also indirectly affects job performance through the mediating role of work engagement. Our findings provide evidence from a Chinese province for future research into relevant topics. The study suggests that the satisfaction among clinicians derived from effective clinical pathway implementation considerably improves their job performance. Therefore, public hospital administrators should take appropriate measures to improve the level of clinicians’ satisfaction with clinical pathway implementation in order to improve the work performance of this group as well as the quality of medical care.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

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Acknowledgements

We would like to thank all the employees who participated in the study.

This work was funded by National Natural Science Foundation of China (Grant No. 71874116 and 72074163), Taikang Yicai Public Health and Epidemic Control Fund (H201203), Sichuan Science and Technology Program, China (Grant No. 2022YFS0052 and 2021YFQ0060), Technological Innovation Miao Zi Project Management Office of Sichuan Province (Grant No. 2020113), Southwest Medical University: Sichuan Hospital Management and Development Research Center, Key Research Base of Humanities and Social Sciences of Sichuan Province (Grant No. SCYG2021-28), Zigong Municipal Science and Technology Bureau (Grant No. 2019rkx08), Health Commission of Zigong (Grant No. 19yb032).

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Junlong Li, Lu Ao & Jay Pan

Sichuan Vocational College of Health and Rehabilitation, Zigong, China

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Concept and design: JL, LA, JP; Data acquisition and analysis: JL, LA; Interpretation of data: JL, LA, JP; Drafting of the manuscript: JL; Critical revision of the manuscript: JL, LA, JP. All authors gave final approval and agreed to be accountable for all aspects of the work.

Corresponding author

Correspondence to Jay Pan .

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Ethics approval and consent to participate.

This study was approved by the Ethics Committee of Sichuan Vocational College of Health and Rehabilitation (CWKY-20211214-28). All surveys were conducted with the informed consent of the participants, who agreed to use the data for this study, without obtaining the names and other identifying information of the respondents, and all data were anonymous and confidential.

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The authors declare no competing interests.

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Li, J., Ao, L. & Pan, J. Satisfaction with clinical pathway implementation versus job performance of clinicians: empirical evidence on the mediating role of work engagement from public hospitals in Sichuan, China. BMC Health Serv Res 24 , 348 (2024). https://doi.org/10.1186/s12913-024-10856-w

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Received : 14 September 2023

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Published : 16 March 2024

DOI : https://doi.org/10.1186/s12913-024-10856-w

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Time to stop using term ‘long Covid’ as symptoms no worse than those after flu, Queensland’s chief health officer says

Researchers compared the symptoms and impairment of Covid and influenza patients a year after they tested positive

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Long Covid may be no different from other post-viral syndromes such as those experienced after flu, according to new research from Queensland Health.

The lead author of the study, the state’s chief health officer Dr John Gerrard, said it was “time to stop using terms like ‘long Covid’” because they imply there is something unique about the longer-term symptoms associated with the virus, and in some cases create hypervigilance.

There are different definitions of long Covid but the World Health Organization defines post-Covid or long Covid as occurring in people still experiencing symptoms three months after their initial Covid-19 infection, when those symptoms can’t be explained by an alternative diagnosis.

The study surveyed 5,112 adults who had symptoms of a respiratory illness and underwent PCR testing between May and June 2022. Of those, 2,399 were positive for Covid-19, 995 positive for influenza and 1,718 negative for both.

A year after their PCR test, participants were asked about ongoing symptoms and impairment using a questionnaire delivered by SMS link.

Overall, 16% reported ongoing symptoms a year later, and 3.6% reported moderate-to-severe impairment in their daily activities.

The results of the study, which Gerrard will present next month at the European Congress of Clinical Microbiology and Infectious Diseases in Barcelona, found no evidence that those who had Covid-19 were more likely to have functional limitations a year on compared with those who did not have Covid-19 (3.0% v 4.1%).

The 3% of the study participants who had ongoing impairments after Covid-19 infection was similar to the 3.4% with ongoing impairments after influenza.

The study also looked at specific symptoms in the patients who had moderate to severe impairment, and found in both patients who were Covid positive and negative, the same percentage (94%) reported one or more of the commonly reported symptoms of long Covid: fatigue, post exertional symptom exacerbation, brain fog and changes to taste and smell.

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Gerrard said long Covid may have appeared to be a distinct and severe illness because of the high number of people infected with Covid-19 within a short period of time, rather than the severity of long Covid symptoms.

“We believe it is time to stop using terms like ‘long Covid’. They wrongly imply there is something unique and exceptional about longer-term symptoms associated with this virus. This terminology can cause unnecessary fear, and in some cases, hypervigilance to longer symptoms that can impede recovery.”

In a press conference on Friday, Gerrard said: “I want to make it clear that the symptoms that some patients described after having Covid-19 are real, and we believe they are real. What we are saying is that the incidence of these symptoms is no greater in Covid-19 than it is with other respiratory viruses, and that to use this term ‘long Covid’ is misleading and I believe harmful.”

The researchers acknowledged the findings are associations and do not represent prevalence, and acknowledged limitations in that participants who attended hospital or had pre-existing illness were not identifiable. They also said because 90% of people in Queensland were vaccinated when Omicron emerged, the lower severity of long Covid could be due to vaccination and the variant.

Prof Philip Britton, a paediatric infectious diseases physician from the University of Sydney and a member of the Long Covid Australia Collaboration, welcomed the study given the lack of published research from Australia in this area.

However, Britton said the conclusion that it was time to stop using terms such as long Covid was “overstated and potentially unhelpful. Long Covid has been a global phenomenon, recognised by WHO.”

Prof Jeremy Nicholson, the director of the Australian National Phenome Centre at Murdoch University, said the question of whether long Covid is unique “cannot be simply answered in this work”.

“The study is observational, based on reported symptoms with no physiological or detailed functional follow-up data. Without laboratory pathophysiological assessment of individual patients, it is impossible to say that this is indistinguishable from flu-related or any other post-viral syndrome,” Nicholson said.

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