what are clinical research studies

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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.

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Clinical Studies in Depth

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

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What Are Clinical Trials?

Talk with your doctor about clinical trials when you discuss treatment options. 

Clinical trials are research studies that test how well new medical approaches work in people. 

What is the purpose of a clinical trial? 

Clinical trials test new ways to find, prevent, and treat cancer. They also help doctors improve the quality of life for people with cancer by testing ways to manage the side effects of cancer and its treatment. 

Why are clinical trials important?

Today, people are living longer lives thanks to results of past cancer clinical trials. When you take part in a clinical trial, you add to our knowledge about cancer and help improve cancer care for people in the future.

People join clinical trials for many reasons. People living with cancer often join trials because they want to help future patients. People with certain risk factors want to help doctors learn how to prevent cancer. Healthy volunteers want to help doctors learn how to find cancer early. 

People with cancer and healthy volunteers join trials to play a role in cancer research and move science forward to help others.  

What are the types of clinical trials?

"I feel that as an African American we do not participate in programs that could BE and sometimes ARE beneficial to us. I hope by my participation this will encourage others African American women to be more open." —Marsha Dukes, NCI clinical trial participant

There are several types of cancer clinical trials. Each type of trial is designed to answer different research questions and will help researchers learn things that can help people in the future.

Treatment Trials

Most cancer clinical trials are treatment studies that involve people who have cancer. These trials test new treatments or new ways of using existing treatments, including new:

• approaches to surgery or radiation therapy
• combinations of treatments

As researchers learn more about the genetic changes that lead to cancer, doctors are testing treatments that target these specific changes. So in some treatment trials, your tumor may be tested to see if treatments targeting specific genetic changes might work better than standard treatments. 

Treatment trials are designed to answers questions such as:

• What is a safe dose of the treatment under study?
• How should the treatment be given?
• Does the treatment help people with cancer live longer than current treatment?
• Can the study treatment shrink tumors or slow their growth and spread?
• What are the treatment's side effects?
• Does the study treatment allow for a better quality of life with fewer side effects?
• Does the treatment help delay the return of the cancer?

Participate in Cancer Prevention Studies

Learn about cancer prevention studies and how to participate.

Prevention Trials

Prevention trials are studies that look at ways to prevent cancer.

In most prevention trials, the people who take part do not have cancer but are at high risk for developing it. Or they have had cancer and are at high risk for developing a new cancer.

There are two kinds of prevention trials, action studies and agent studies. In action studies, you are asked to do something, such as exercise or follow a special diet. In agent studies, you are asked to take something, such as a drug or vitamin. Learn about participating in prevention studies .

Researchers who conduct these studies want to know:

• How safe is the drug or activity?
• Does the new approach reduce the chance that someone will get cancer?

Cancer Screening Studies

Learn more about joining a screening trial to help find cancer early.

Screening Trials

The goal of cancer screening trials is to test ways to find cancer before it causes symptoms, when it may be easier to treat.

An effective screening test will reduce the number of people who die from the cancer that is being screened for. Learn about joining a cancer screening study . 

But screening tests can have harms, which include bleeding or other physical damage. Other possible harms include a result that shows you might have cancer when you don’t. When this happens, it may lead to unnecessary tests and procedures. On the other hand, the results may show no signs of cancer when you have it. And sometimes screening can find cancers that would not have harmed you during your lifetime.

Researchers who conduct cancer screening studies want to know:

• Does finding disease earlier, before people have any symptoms, save lives?
• Is one screening test better than another?
• Do the benefits of the screening test outweigh the harms?

Supportive Care/Palliative Care Trials

These trials look at ways to improve the quality of life of people with cancer, especially those who have side effects from cancer and its treatment.

They might test drugs, such as those that help with depression or nausea. Or they might test activities, such as attending support groups, exercising, or talking with a counselor.

Some of these trials test ways to help families and caregivers cope with their own needs, as well as those of the person with cancer.

• How does cancer and its treatment affect patients and their loved ones?
• What can improve the comfort and quality of life of people who have cancer?

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Clinical Trials: What Patients Need to Know

Learn more about clinical trials and find a trial that might be right for you. Clinical trials are voluntary research studies conducted in people and designed to answer specific questions about the safety or effectiveness of drugs, vaccines, other therapies, or new ways of using existing treatments. It is important to remember that the FDA does not conduct Clinical Trials.

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Enter a word or phrase, such as the name of a medical condition or intervention. Example: Cancer AND Los Angeles or expanded access AND compassionate use  

Learn More About Clinical Trials

Clinical Research Versus Medical Treatment Understand the differences between clinical research and medical treatment and what those differences mean for you. Find answers to your questions about clinical trials, such as why they are done, who should consider participating, and issues to consider before joining a trial.

What are the Different Types of Clinical Research Understand the different types of research and the four clinical trial phases, such as their purpose and how many people participate in each of the phases.

Informed Consent for Clinical Trials Understand what informed consent is and the questions you need to know before signing informed consent.

Diversity in Clinical Trial Participation It is important to test drugs and medical products in the people they are meant to help. Learn about FDASIA 907 and how FDA works to make sure that people of different ages, races, ethnic groups, and genders are included in clinical trials.

What is an Institutional Review Board Understand what Institutional Review Boards are, who is on them and who they protect. 

Sexual and Gender Minorities The NIH Sexual and Gender Minority Research Office (SGMRO) coordinates sexual and gender minority (SGM)--related research and activities by working directly with the NIH Institutes, Centers, and Offices. The office was officially established in September 2015 within the NIH Division of Program Coordination, Planning, and Strategic Initiatives (DPCPSI).

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More information, about clinical center, clinical trials and you, participate in a study, referring a patient, about clinical research.

Research participants are partners in discovery at the NIH Clinical Center, the largest research hospital in America. Clinical research is medical research involving people The Clinical Center provides hope through pioneering clinical research to improve human health. We rapidly translate scientific observations and laboratory discoveries into new ways to diagnose, treat and prevent disease. More than 500,000 people from around the world have participated in clinical research since the hospital opened in 1953. We do not charge patients for participation and treatment in clinical studies at NIH. In certain emergency circumstances, you may qualify for help with travel and other expenses Read more , to see if clinical studies are for you.

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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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What is Clinical Research?

February 10, 2021

Clinical trials are part of clinical research and at the heart of all medical advances. Clinical trials look at new ways to prevent, detect, or treat disease. You might also hear clinical research referred to as clinical studies, clinical trials, studies, research, trials, or protocols.

People can participate either as a patient with a diagnosis or as a healthy volunteer.

People with the condition being studied may participate in studies that look at developing new treatments, identifying causes of illnesses, studying trends, or evaluating how genetics may be related to an illness.

Healthy volunteers are needed to compare their results to the results of people with the illness being studied.

Some studies do not require participants to change their current treatment, while other studies do. Studies might use brain scans, psychological tests, behavioral observation, or blood tests for genetic evaluation.

People participate in clinical trials for a variety of reasons. Healthy volunteers say they participate to help others and to contribute to moving science forward. Participants with an illness or disease also participate to help others, but also to possibly receive the newest treatment and to have the additional care and attention from the clinical trial staff.

Research is our best hope for understanding and treating mental illnesses. Thanks to help from volunteers, researchers are learning more and more about the causes of mental and behavioral disorders and are finding new ways to treat and prevent illnesses. Without this important relationship between research participants and those studying their illnesses, it would be much more difficult to improve health treatments.

Volunteers of all ethnic and cultural backgrounds are needed. By having a variety of volunteers participate, researchers can learn how different people react to medications and other treatments.

Thank you for your interest in learning more about clinical research!

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Clinical research study designs: The essentials

Ambika g. chidambaram.

1 Children's Hospital of Philadelphia, Philadelphia Pennsylvania, USA

Maureen Josephson

In clinical research, our aim is to design a study which would be able to derive a valid and meaningful scientific conclusion using appropriate statistical methods. The conclusions derived from a research study can either improve health care or result in inadvertent harm to patients. Hence, this requires a well‐designed clinical research study that rests on a strong foundation of a detailed methodology and governed by ethical clinical principles. The purpose of this review is to provide the readers an overview of the basic study designs and its applicability in clinical research.

Introduction

In clinical research, our aim is to design a study, which would be able to derive a valid and meaningful scientific conclusion using appropriate statistical methods that can be translated to the “real world” setting. 1 Before choosing a study design, one must establish aims and objectives of the study, and choose an appropriate target population that is most representative of the population being studied. The conclusions derived from a research study can either improve health care or result in inadvertent harm to patients. Hence, this requires a well‐designed clinical research study that rests on a strong foundation of a detailed methodology and is governed by ethical principles. 2

From an epidemiological standpoint, there are two major types of clinical study designs, observational and experimental. 3 Observational studies are hypothesis‐generating studies, and they can be further divided into descriptive and analytic. Descriptive observational studies provide a description of the exposure and/or the outcome, and analytic observational studies provide a measurement of the association between the exposure and the outcome. Experimental studies, on the other hand, are hypothesis testing studies. It involves an intervention that tests the association between the exposure and outcome. Each study design is different, and so it would be important to choose a design that would most appropriately answer the question in mind and provide the most valuable information. We will be reviewing each study design in detail (Figure  1 ).

Overview of clinical research study designs

Observational study designs

Observational studies ask the following questions: what, who, where and when. There are many study designs that fall under the umbrella of descriptive study designs, and they include, case reports, case series, ecologic study, cross‐sectional study, cohort study and case‐control study (Figure  2 ).

Classification of observational study designs

Case reports and case series

Every now and then during clinical practice, we come across a case that is atypical or ‘out of the norm’ type of clinical presentation. This atypical presentation is usually described as case reports which provides a detailed and comprehensive description of the case. 4 It is one of the earliest forms of research and provides an opportunity for the investigator to describe the observations that make a case unique. There are no inferences obtained and therefore cannot be generalized to the population which is a limitation. Most often than not, a series of case reports make a case series which is an atypical presentation found in a group of patients. This in turn poses the question for a new disease entity and further queries the investigator to look into mechanistic investigative opportunities to further explore. However, in a case series, the cases are not compared to subjects without the manifestations and therefore it cannot determine which factors in the description are unique to the new disease entity.

Ecologic study

Ecological studies are observational studies that provide a description of population group characteristics. That is, it describes characteristics to all individuals within a group. For example, Prentice et al 5 measured incidence of breast cancer and per capita intake of dietary fat, and found a correlation that higher per capita intake of dietary fat was associated with an increased incidence of breast cancer. But the study does not conclude specifically which subjects with breast cancer had a higher dietary intake of fat. Thus, one of the limitations with ecologic study designs is that the characteristics are attributed to the whole group and so the individual characteristics are unknown.

Cross‐sectional study

Cross‐sectional studies are study designs used to evaluate an association between an exposure and outcome at the same time. It can be classified under either descriptive or analytic, and therefore depends on the question being answered by the investigator. Since, cross‐sectional studies are designed to collect information at the same point of time, this provides an opportunity to measure prevalence of the exposure or the outcome. For example, a cross‐sectional study design was adopted to estimate the global need for palliative care for children based on representative sample of countries from all regions of the world and all World Bank income groups. 6 The limitation of cross‐sectional study design is that temporal association cannot be established as the information is collected at the same point of time. If a study involves a questionnaire, then the investigator can ask questions to onset of symptoms or risk factors in relation to onset of disease. This would help in obtaining a temporal sequence between the exposure and outcome. 7

Case‐control study

Case‐control studies are study designs that compare two groups, such as the subjects with disease (cases) to the subjects without disease (controls), and to look for differences in risk factors. 8 This study is used to study risk factors or etiologies for a disease, especially if the disease is rare. Thus, case‐control studies can also be hypothesis testing studies and therefore can suggest a causal relationship but cannot prove. It is less expensive and less time‐consuming than cohort studies (described in section “Cohort study”). An example of a case‐control study was performed in Pakistan evaluating the risk factors for neonatal tetanus. They retrospectively reviewed a defined cohort for cases with and without neonatal tetanus. 9 They found a strong association of the application of ghee (clarified butter) as a risk factor for neonatal tetanus. Although this suggests a causal relationship, cause cannot be proven by this methodology (Figure  3 ).

Case‐control study design

One of the limitations of case‐control studies is that they cannot estimate prevalence of a disease accurately as a proportion of cases and controls are studied at a time. Case‐control studies are also prone to biases such as recall bias, as the subjects are providing information based on their memory. Hence, the subjects with disease are likely to remember the presence of risk factors compared to the subjects without disease.

One of the aspects that is often overlooked is the selection of cases and controls. It is important to select the cases and controls appropriately to obtain a meaningful and scientifically sound conclusion and this can be achieved by implementing matching. Matching is defined by Gordis et al as ‘the process of selecting the controls so that they are similar to the cases in certain characteristics such as age, race, sex, socioeconomic status and occupation’ 7 This would help identify risk factors or probable etiologies that are not due to differences between the cases and controls.

Cohort study

Cohort studies are study designs that compare two groups, such as the subjects with exposure/risk factor to the subjects without exposure/risk factor, for differences in incidence of outcome/disease. Most often, cohort study designs are used to study outcome(s) from a single exposure/risk factor. Thus, cohort studies can also be hypothesis testing studies and can infer and interpret a causal relationship between an exposure and a proposed outcome, but cannot establish it (Figure  4 ).

Cohort study design

Cohort studies can be classified as prospective and retrospective. 7 Prospective cohort studies follow subjects from presence of risk factors/exposure to development of disease/outcome. This could take up to years before development of disease/outcome, and therefore is time consuming and expensive. On the other hand, retrospective cohort studies identify a population with and without the risk factor/exposure based on past records and then assess if they had developed the disease/outcome at the time of study. Thus, the study design for prospective and retrospective cohort studies are similar as we are comparing populations with and without exposure/risk factor to development of outcome/disease.

Cohort studies are typically chosen as a study design when the suspected exposure is known and rare, and the incidence of disease/outcome in the exposure group is suspected to be high. The choice between prospective and retrospective cohort study design would depend on the accuracy and reliability of the past records regarding the exposure/risk factor.

Some of the biases observed with cohort studies include selection bias and information bias. Some individuals who have the exposure may refuse to participate in the study or would be lost to follow‐up, and in those instances, it becomes difficult to interpret the association between an exposure and outcome. Also, if the information is inaccurate when past records are used to evaluate for exposure status, then again, the association between the exposure and outcome becomes difficult to interpret.

Case‐control studies based within a defined cohort

Case‐control studies based within a defined cohort is a form of study design that combines some of the features of a cohort study design and a case‐control study design. When a defined cohort is embedded in a case‐control study design, all the baseline information collected before the onset of disease like interviews, surveys, blood or urine specimens, then the cohort is followed onset of disease. One of the advantages of following the above design is that it eliminates recall bias as the information regarding risk factors is collected before onset of disease. Case‐control studies based within a defined cohort can be further classified into two types: Nested case‐control study and Case‐cohort study.

Nested case‐control study

A nested case‐control study consists of defining a cohort with suspected risk factors and assigning a control within a cohort to the subject who develops the disease. 10 Over a period, cases and controls are identified and followed as per the investigator's protocol. Hence, the case and control are matched on calendar time and length of follow‐up. When this study design is implemented, it is possible for the control that was selected early in the study to develop the disease and become a case in the latter part of the study.

Case‐cohort Study

A case‐cohort study is similar to a nested case‐control study except that there is a defined sub‐cohort which forms the groups of individuals without the disease (control), and the cases are not matched on calendar time or length of follow‐up with the control. 11 With these modifications, it is possible to compare different disease groups with the same sub‐cohort group of controls and eliminates matching between the case and control. However, these differences will need to be accounted during analysis of results.

Experimental study design

The basic concept of experimental study design is to study the effect of an intervention. In this study design, the risk factor/exposure of interest/treatment is controlled by the investigator. Therefore, these are hypothesis testing studies and can provide the most convincing demonstration of evidence for causality. As a result, the design of the study requires meticulous planning and resources to provide an accurate result.

The experimental study design can be classified into 2 groups, that is, controlled (with comparison) and uncontrolled (without comparison). 1 In the group without controls, the outcome is directly attributed to the treatment received in one group. This fails to prove if the outcome was truly due to the intervention implemented or due to chance. This can be avoided if a controlled study design is chosen which includes a group that does not receive the intervention (control group) and a group that receives the intervention (intervention/experiment group), and therefore provide a more accurate and valid conclusion.

Experimental study designs can be divided into 3 broad categories: clinical trial, community trial, field trial. The specifics of each study design are explained below (Figure  5 ).

Experimental study designs

Clinical trial

Clinical trials are also known as therapeutic trials, which involve subjects with disease and are placed in different treatment groups. It is considered a gold standard approach for epidemiological research. One of the earliest clinical trial studies was performed by James Lind et al in 1747 on sailors with scurvy. 12 Lind divided twelve scorbutic sailors into six groups of two. Each group received the same diet, in addition to a quart of cider (group 1), twenty‐five drops of elixir of vitriol which is sulfuric acid (group 2), two spoonfuls of vinegar (group 3), half a pint of seawater (group 4), two oranges and one lemon (group 5), and a spicy paste plus a drink of barley water (group 6). The group who ate two oranges and one lemon had shown the most sudden and visible clinical effects and were taken back at the end of 6 days as being fit for duty. During Lind's time, this was not accepted but was shown to have similar results when repeated 47 years later in an entire fleet of ships. Based on the above results, in 1795 lemon juice was made a required part of the diet of sailors. Thus, clinical trials can be used to evaluate new therapies, such as new drug or new indication, new drug combination, new surgical procedure or device, new dosing schedule or mode of administration, or a new prevention therapy.

While designing a clinical trial, it is important to select the population that is best representative of the general population. Therefore, the results obtained from the study can be generalized to the population from which the sample population was selected. It is also as important to select appropriate endpoints while designing a trial. Endpoints need to be well‐defined, reproducible, clinically relevant and achievable. The types of endpoints include continuous, ordinal, rates and time‐to‐event, and it is typically classified as primary, secondary or tertiary. 2 An ideal endpoint is a purely clinical outcome, for example, cure/survival, and thus, the clinical trials will become very long and expensive trials. Therefore, surrogate endpoints are used that are biologically related to the ideal endpoint. Surrogate endpoints need to be reproducible, easily measured, related to the clinical outcome, affected by treatment and occurring earlier than clinical outcome. 2

Clinical trials are further divided into randomized clinical trial, non‐randomized clinical trial, cross‐over clinical trial and factorial clinical trial.

Randomized clinical trial

A randomized clinical trial is also known as parallel group randomized trials or randomized controlled trials. Randomized clinical trials involve randomizing subjects with similar characteristics to two groups (or multiple groups): the group that receives the intervention/experimental therapy and the other group that received the placebo (or standard of care). 13 This is typically performed by using a computer software, manually or by other methods. Hence, we can measure the outcomes and efficacy of the intervention/experimental therapy being studied without bias as subjects have been randomized to their respective groups with similar baseline characteristics. This type of study design is considered gold standard for epidemiological research. However, this study design is generally not applicable to rare and serious disease process as it would unethical to treat that group with a placebo. Please see section “Randomization” for detailed explanation regarding randomization and placebo.

Non‐randomized clinical trial

A non‐randomized clinical trial involves an approach to selecting controls without randomization. With this type of study design a pattern is usually adopted, such as, selection of subjects and controls on certain days of the week. Depending on the approach adopted, the selection of subjects becomes predictable and therefore, there is bias with regards to selection of subjects and controls that would question the validity of the results obtained.

Historically controlled studies can be considered as a subtype of non‐randomized clinical trial. In this study design subtype, the source of controls is usually adopted from the past, such as from medical records and published literature. 1 The advantages of this study design include being cost‐effective, time saving and easily accessible. However, since this design depends on already collected data from different sources, the information obtained may not be accurate, reliable, lack uniformity and/or completeness as well. Though historically controlled studies maybe easier to conduct, the disadvantages will need to be taken into account while designing a study.

Cross‐over clinical trial

In cross‐over clinical trial study design, there are two groups who undergoes the same intervention/experiment at different time periods of the study. That is, each group serves as a control while the other group is undergoing the intervention/experiment. 14 Depending on the intervention/experiment, a ‘washout’ period is recommended. This would help eliminate residuals effects of the intervention/experiment when the experiment group transitions to be the control group. Hence, the outcomes of the intervention/experiment will need to be reversible as this type of study design would not be possible if the subject is undergoing a surgical procedure.

Factorial trial

A factorial trial study design is adopted when the researcher wishes to test two different drugs with independent effects on the same population. Typically, the population is divided into 4 groups, the first with drug A, the second with drug B, the third with drug A and B, and the fourth with neither drug A nor drug B. The outcomes for drug A are compared to those on drug A, drug A and B and to those who were on drug B and neither drug A nor drug B. 15 The advantages of this study design that it saves time and helps to study two different drugs on the same study population at the same time. However, this study design would not be applicable if either of the drugs or interventions overlaps with each other on modes of action or effects, as the results obtained would not attribute to a particular drug or intervention.

Community trial

Community trials are also known as cluster‐randomized trials, involve groups of individuals with and without disease who are assigned to different intervention/experiment groups. Hence, groups of individuals from a certain area, such as a town or city, or a certain group such as school or college, will undergo the same intervention/experiment. 16 Hence, the results will be obtained at a larger scale; however, will not be able to account for inter‐individual and intra‐individual variability.

Field trial

Field trials are also known as preventive or prophylactic trials, and the subjects without the disease are placed in different preventive intervention groups. 16 One of the hypothetical examples for a field trial would be to randomly assign to groups of a healthy population and to provide an intervention to a group such as a vitamin and following through to measure certain outcomes. Hence, the subjects are monitored over a period of time for occurrence of a particular disease process.

Overview of methodologies used within a study design

Randomization.

Randomization is a well‐established methodology adopted in research to prevent bias due to subject selection, which may impact the result of the intervention/experiment being studied. It is one of the fundamental principles of an experimental study designs and ensures scientific validity. It provides a way to avoid predicting which subjects are assigned to a certain group and therefore, prevent bias on the final results due to subject selection. This also ensures comparability between groups as most baseline characteristics are similar prior to randomization and therefore helps to interpret the results regarding the intervention/experiment group without bias.

There are various ways to randomize and it can be as simple as a ‘flip of a coin’ to use computer software and statistical methods. To better describe randomization, there are three types of randomization: simple randomization, block randomization and stratified randomization.

Simple randomization

In simple randomization, the subjects are randomly allocated to experiment/intervention groups based on a constant probability. That is, if there are two groups A and B, the subject has a 0.5 probability of being allocated to either group. This can be performed in multiple ways, and one of which being as simple as a ‘flip of a coin’ to using random tables or numbers. 17 The advantage of using this methodology is that it eliminates selection bias. However, the disadvantage with this methodology is that an imbalance in the number allocated to each group as well as the prognostic factors between groups. Hence, it is more challenging in studies with a small sample size.

Block randomization

In block randomization, the subjects of similar characteristics are classified into blocks. The aim of block randomization is to balance the number of subjects allocated to each experiment/intervention group. For example, let's assume that there are four subjects in each block, and two of the four subjects in each block will be randomly allotted to each group. Therefore, there will be two subjects in one group and two subjects in the other group. 17 The disadvantage with this methodology is that there is still a component of predictability in the selection of subjects and the randomization of prognostic factors is not performed. However, it helps to control the balance between the experiment/intervention groups.

Stratified randomization

In stratified randomization, the subjects are defined based on certain strata, which are covariates. 18 For example, prognostic factors like age can be considered as a covariate, and then the specified population can be randomized within each age group related to an experiment/intervention group. The advantage with this methodology is that it enables comparability between experiment/intervention groups and thus makes result analysis more efficient. But, with this methodology the covariates will need to be measured and determined before the randomization process. The sample size will help determine the number of strata that would need to be chosen for a study.

Blinding is a methodology adopted in a study design to intentionally not provide information related to the allocation of the groups to the subject participants, investigators and/or data analysts. 19 The purpose of blinding is to decrease influence associated with the knowledge of being in a particular group on the study result. There are 3 forms of blinding: single‐blinded, double‐blinded and triple‐blinded. 1 In single‐blinded studies, otherwise called as open‐label studies, the subject participants are not revealed which group that they have been allocated to. However, the investigator and data analyst will be aware of the allocation of the groups. In double‐blinded studies, both the study participants and the investigator will be unaware of the group to which they were allocated to. Double‐blinded studies are typically used in clinical trials to test the safety and efficacy of the drugs. In triple‐blinded studies, the subject participants, investigators and data analysts will not be aware of the group allocation. Thus, triple‐blinded studies are more difficult and expensive to design but the results obtained will exclude confounding effects from knowledge of group allocation.

Blinding is especially important in studies where subjective response are considered as outcomes. This is because certain responses can be modified based on the knowledge of the experiment group that they are in. For example, a group allocated in the non‐intervention group may not feel better as they are not getting the treatment, or an investigator may pay more attention to the group receiving treatment, and thereby potentially affecting the final results. However, certain treatments cannot be blinded such as surgeries or if the treatment group requires an assessment of the effect of intervention such as quitting smoking.

Placebo is defined in the Merriam‐Webster dictionary as ‘an inert or innocuous substance used especially in controlled experiments testing the efficacy of another substance (such as drug)’. 20 A placebo is typically used in a clinical research study to evaluate the safety and efficacy of a drug/intervention. This is especially useful if the outcome measured is subjective. In clinical drug trials, a placebo is typically a drug that resembles the drug to be tested in certain characteristics such as color, size, shape and taste, but without the active substance. This helps to measure effects of just taking the drug, such as pain relief, compared to the drug with the active substance. If the effect is positive, for example, improvement in mood/pain, then it is called placebo effect. If the effect is negative, for example, worsening of mood/pain, then it is called nocebo effect. 21

The ethics of placebo‐controlled studies is complex and remains a debate in the medical research community. According to the Declaration of Helsinki on the use of placebo released in October 2013, “The benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best proven intervention(s), except in the following circumstances:

Where no proven intervention exists, the use of placebo, or no intervention, is acceptable; or

Where for compelling and scientifically sound methodological reasons the use of any intervention less effective than the best proven one, the use of placebo, or no intervention is necessary to determine the efficacy or safety of an intervention and the patients who receive any intervention less effective than the best proven one, placebo, or no intervention will not be subject to additional risks of serious or irreversible harm as a result of not receiving the best proven intervention.

Extreme care must be taken to avoid abuse of this option”. 22

Hence, while designing a research study, both the scientific validity and ethical aspects of the study will need to be thoroughly evaluated.

Bias has been defined as “any systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposure's effect on the risk of disease”. 23 There are multiple types of biases and so, in this review we will focus on the following types: selection bias, information bias and observer bias. Selection bias is when a systematic error is committed while selecting subjects for the study. Selection bias will affect the external validity of the study if the study subjects are not representative of the population being studied and therefore, the results of the study will not be generalizable. Selection bias will affect the internal validity of the study if the selection of study subjects in each group is influenced by certain factors, such as, based on the treatment of the group assigned. One of the ways to decrease selection bias is to select the study population that would representative of the population being studied, or to randomize (discussed in section “Randomization”).

Information bias is when a systematic error is committed while obtaining data from the study subjects. This can be in the form of recall bias when subject is required to remember certain events from the past. Typically, subjects with the disease tend to remember certain events compared to subjects without the disease. Observer bias is a systematic error when the study investigator is influenced by the certain characteristics of the group, that is, an investigator may pay closer attention to the group receiving the treatment versus the group not receiving the treatment. This may influence the results of the study. One of the ways to decrease observer bias is to use blinding (discussed in section “Blinding”).

Thus, while designing a study it is important to take measure to limit bias as much as possible so that the scientific validity of the study results is preserved to its maximum.

Overview of drug development in the United States of America

Now that we have reviewed the various clinical designs, clinical trials form a major part in development of a drug. In the United States, the Food and Drug Administration (FDA) plays an important role in getting a drug approved for clinical use. It includes a robust process that involves four different phases before a drug can be made available to the public. Phase I is conducted to determine a safe dose. The study subjects consist of normal volunteers and/or subjects with disease of interest, and the sample size is typically small and not more than 30 subjects. The primary endpoint consists of toxicity and adverse events. Phase II is conducted to evaluate of safety of dose selected in Phase I, to collect preliminary information on efficacy and to determine factors to plan a randomized controlled trial. The study subjects consist of subjects with disease of interest and the sample size is also small but more that Phase I (40–100 subjects). The primary endpoint is the measure of response. Phase III is conducted as a definitive trial to prove efficacy and establish safety of a drug. Phase III studies are randomized controlled trials and depending on the drug being studied, it can be placebo‐controlled, equivalence, superiority or non‐inferiority trials. The study subjects consist of subjects with disease of interest, and the sample size is typically large but no larger than 300 to 3000. Phase IV is performed after a drug is approved by the FDA and it is also called the post‐marketing clinical trial. This phase is conducted to evaluate new indications, to determine safety and efficacy in long‐term follow‐up and new dosing regimens. This phase helps to detect rare adverse events that would not be picked up during phase III studies and decrease in the delay in the release of the drug in the market. Hence, this phase depends heavily on voluntary reporting of side effects and/or adverse events by physicians, non‐physicians or drug companies. 2

We have discussed various clinical research study designs in this comprehensive review. Though there are various designs available, one must consider various ethical aspects of the study. Hence, each study will require thorough review of the protocol by the institutional review board before approval and implementation.

CONFLICT OF INTEREST

Chidambaram AG, Josephson M. Clinical research study designs: The essentials . Pediatr Invest . 2019; 3 :245‐252. 10.1002/ped4.12166 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]

About Clinical Research

Clinical research studies the safety and effectiveness of new medical treatments, drugs, devices, or interventions in humans. It involves carefully designed studies conducted with volunteer participants to gather data on the potential benefits and risks of these interventions. Clinical research is essential for advancing medical knowledge, improving patient care, developing new treatments for diseases and health condition, and contributing to the prevention, diagnosis, and treatment of diseases and health conditions. 

Two main types of clinical research studies are observational studies and interventional studies. Observational studies observe participants in their natural environment or during routine medical care to gather information about their health outcomes. Interventional studies, also known as clinical trials, these studies involve the administration of a specific intervention (such as a new drug, treatment, or medical device) to evaluate its effects on participants' health outcomes.

The Pre-screening Process

Eligibility to participate in a research program is determined through a careful screening process. The first step is an online screening, which can be accessed from the link below. The online screening is will ask about your physical and mental health to determine if a study is a good fit for you. You can expect the online screening to take 30-60 minutes. If a study seems to be a good match based upon the online screening, a study team member will contact you and discuss the study in more detail, answer questions you may have about the study, and send a copy of the informed consent form to read prior to enrolling in the research study.  

The Screening Process

If you are still interested in participating, you will meet with a member of the research team, virtually or in person, to review the consent form and answer your questions. The consent form will explain the purpose of the study, its procedures, potential risks and benefits, and your rights as a participant. If you are interested in participating after reviewing the consent form, it will be signed by you and the person obtaining your consent. 

The next step will to be evaluated at an in-person or hybrid virtual/in-person screening. The screening process may include interviews to assess physical and mental health, lab work, and the review of your medical records, according to the research protocol set for each study.

Participating in a Clincial Study or Trial

Participation in one of the clinic's research studies involves coming to Stanford for regular visits. During study visits, study participants typically meet with a research psychiatrist and a research coordinator. While meeting with the research psychiatrist, participants discuss current depression symptoms and any medical issues related to the treatment. Participants may meet with a member of the research team who is trained to administer certain psychiatric assessments. These assessments allow the research team to thoroughly monitor the participant’s symptoms of depression throughout the course of the research study.

Most studies conducted in the Depression Research Clinic involve treatment with study medication. The only exceptions are occasional device studies, such as transcranial magnetic stimulation (TMS) or observational studies where participants may complete questionnaires or various tests such as MRI.  Study medication received as part of a research study is provided to participants at no cost.

Other Considerations

Participation in a research study offers several advantages. All study-related clinic visits, psychiatric evaluations, physical examinations, laboratory work, and medications are provided at no cost to eligible participants. This is a considerable benefit, given the rising costs of mental healthcare. In addition, highly trained professionals at Stanford University assess research participants on a regular basis to ensure comprehensive care.

However, there can be disadvantages to being a research participant. Study visits may take more time than what is typically required as an average patient and include the completion of a variety of questionnaires, as well as answering questions about depression symptoms. Moreover, research protocols frequently limit the dosing of the study medication, and often restrict the use of medications other than those being studied. In some double-blind studies, participants have the possibility of receiving placebo (sugar pill) instead of the active medication. Before enrolling in any study, potential participants will be told of the possibility and percent chance of being placed in the placebo group. Follow-up care may be provided for a limited time after participation in a placebo-controlled study. Most research appointments are scheduled Monday through Friday between the hours of 7:00 a.m. and 5:00 p.m. Within that time frame, we do try to be as flexible as possible to accommodate participants' schedules.

Clinical research is vital for advancing medical science, improving patient care, and ultimately saving lives. Without clinical research, many of the medical treatments and interventions that we rely on today would not exist. Ultimately, participating in a clinical trial is a personal decision that should be made based on careful consideration of the potential risks and benefits, as well as discussions with your healthcare provider and the research team conducting the trial.

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Clinical research is the study of health and illness in people.

Scientists may have many reasons for doing a clinical study, such as:

• To explore the cause of a disease or a set of symptoms
• To test if a treatment will help with a symptom or condition
• To learn how a certain behavior affects people’s health

Different types of clinical studies are used in different circumstances. Depending on what is known and what isn’t, scientists may even study the same research question using different kinds of studies and in different groups of people. Here are different types of clinical studies and why they might be used.

Observational Studies

In many studies, researchers do not do experiments or test new treatments; they observe. Observational studies help researchers understand a situation and come up with hypotheses that can be put to the test in clinical trials.

Observational studies can find associations between things but can’t prove that one thing causes another. Types include:

Case Study/Case Series

A detailed description of one or more patients. By documenting new and unusual cases, researchers start to generate hypotheses about causes or risk factors.

• Epidemiological Study

Compares the rate of a disease or condition for groups of people, such as towns in different climates or with different average incomes.

• Cross-Sectional Study

A snapshot of many people at one moment in time. These studies can show how common a condition is and help identify factors associated with it.

Case-Control Study

A group of people who have a condition is compared to a control group of people who don’t. Possible causes or risk factors can emerge.

Cohort Study

A large group of people is observed over time. Some eventually develop a disease or condition. Researchers can learn how often the condition occurs and find possible causes or risk factors.

Clinical Trials

In these studies, researchers test new ways to prevent, detect, or treat disease. Treatments might be new drugs or combinations of drugs, new surgical procedures or devices, or new ways to use existing treatments. Clinical trials can also test other aspects of care, such as ways to improve the quality of life for people with chronic illnesses.

A well-designed clinical trial is the gold standard for proving that a treatment or medical approach works, but clinical trials can’t always be used. For example,

scientists can’t randomly assign people to live in different places, or ask people to start smoking or eating an unhealthy diet. Clinical trials are conducted in phases:

• Purpose: Find out whether a medical approach (e.g., drug, diagnostic test, device) is safe, identify side effects, and figure out appropriate doses.
• Number of people: Typically, fewer than 100
• Purpose: Start testing whether a medical approach works. Continue monitoring for side effects; get information that goes into designing a large, phase III trial.
• Number of people: Typically, 100-300
• Purpose: Prove whether a medical approach works; continue monitoring side effects.
• Number of people: As many as needed or able to enroll—can be 1,000 or more
• Purpose: When a medical approach is being marketed, continue gathering information on its effects.
• Number of people: Thousands

How good are these kinds of studies at showing cause and effect?

The strength of a study depends on its size and design. New results may confirm earlier findings, contradict them, or add new aspects to scientists’ understanding. In the end, cause and effect are usually hard to establish without a well-designed clinical trial.

Least Effective to Most Effective:

• Case-Control Study/Cohort Study
• Case Study/Series
• Clinical Trial

What can I do to help?

You’ve begun! Learning about what results mean will help you make good choices with your health care provider.

You could also consider volunteering either as a healthy volunteer or as a participant who has a particular disease or condition.

For more information about clinical trials:

ClinicalResearchTrials.nih.gov

[email protected]

Produced by the National Institutes of Health, the largest source of public funding for medical research in the world. NIH’s mission is to seek fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to enhance health, lengthen life, and reduce illness and disability.

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Digital Health Technology (DHT) in European Clinical Trials, How to Improve the Status-Quo of the Regulatory Landscape?

• Published: 24 April 2024

Cite this article

• Hans-Peter Podhaisky   ORCID: orcid.org/0000-0003-3414-9252 1  

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Digital health technology (DHT) is increasingly used to facilitate the conduct of clinical drug trials. The European regulatory environment would benefit from some adjustments to realize the full potential of DHTs. Considering current discussions such as the European Accelerating Clinical Trial Initiative (ACT EU), we propose four concrete adjustments to this regulatory landscape to introduce risk-based qualification approaches for DHTs. In our view, these changes would have the potential to facilitate the use of DHT in clinical research and thus provide access to innovative therapies in Europe.

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Podhaisky, HP. Digital Health Technology (DHT) in European Clinical Trials, How to Improve the Status-Quo of the Regulatory Landscape?. Ther Innov Regul Sci (2024). https://doi.org/10.1007/s43441-024-00657-y

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DOI : https://doi.org/10.1007/s43441-024-00657-y

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Science, health, and public trust.

October 18, 2016

Understanding Clinical Studies

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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 Research Nurse

• Madison, Wisconsin
• SCHOOL OF MEDICINE AND PUBLIC HEALTH/CARBONE COMP CANCER CENTER
• Health and Wellness Services
• Partially Remote
• Staff-Full Time
• Staff-Part Time
• Opening at: Apr 26 2024 at 14:25 CDT
• Closing at: May 10 2024 at 23:55 CDT

Job Summary:

The Clinical Research Nurse will join the Clinical Research Central Office (CRCO) at the University of Wisconsin Carbone Cancer Center (UWCCC) to coordinate cancer clinical research within one or more Disease-Oriented Teams. The primary duties of this job involve the management of subjects enrolled in clinical research studies at the UW Carbone Cancer Center. This position will report to the Clinical Team Manager and work under the general direction of the Principal Investigator of each research study. This position has the ability to work remotely 1 day/week and does not include any nights or weekends. Prefer full time FTE, but will consider down to 0.8 FTE for the right candidate. The Clinical Research Nurse must have a high degree of clinical expertise with a specific focus on the treatment of patients with anticancer agents and a specialized nursing competence in the field of Oncology Research.

Responsibilities:

• 10% Secures and schedules logistics for clinical research projects according to the research plan
• 10% Assists in the recruitment and screening of subjects for clinical studies by conducting physical health assessments
• 10% Provides professional nursing care to patients according to established protocols
• 15% Provides appropriate treatment plan direction and information to study participants
• 20% Serves as main point of contact and liaison to project participants, investigators, research sponsors, and the research team delivering study information in accordance with established research project standards and protocols
• 10% Collects, verifies, and enters data into database and analyzes clinical information data
• 15% Serves a primary point of contact for emergent study participant situations related to adverse effects or complications of the study
• 10% May provide expertise, training, and guidance to the community, peers, and/or students

Institutional Statement on Diversity:

Diversity is a source of strength, creativity, and innovation for UW-Madison. We value the contributions of each person and respect the profound ways their identity, culture, background, experience, status, abilities, and opinion enrich the university community. We commit ourselves to the pursuit of excellence in teaching, research, outreach, and diversity as inextricably linked goals. The University of Wisconsin-Madison fulfills its public mission by creating a welcoming and inclusive community for people from every background - people who as students, faculty, and staff serve Wisconsin and the world. For more information on diversity and inclusion on campus, please visit: Diversity and Inclusion

Preferred Bachelor's Degree Nursing

Qualifications:

Minimum one year nursing experience required. Candidates should have exceptional clinical nursing skills and expertise coupled with a strong interest in clinical research. Prior experience working with Oncology patients is preferred. Prior clinical research experience preferred. License/Certification should also include BLS certification required

License/Certification:

Required RN - Registered Nurse - State Licensure And/Or Compact State Licensure Required BCLS - Basic Life Support

Full or Part Time: 80% - 100% This position may require some work to be performed in-person, onsite, at a designated campus work location. Some work may be performed remotely, at an offsite, non-campus work location.

Appointment Type, Duration:

Ongoing/Renewable

Minimum $68,000 ANNUAL (12 months) Depending on Qualifications

Additional Information:

- Work experience should demonstrate dependability, flexibility, and maturity. Candidates must be effective at building interpersonal relationships with constructive interactions, be clear and effective communicators, promote and create collegial environments that value accountability. Employees will also be expected to uphold UWCCC core values as defined below: - Respect: Demonstrate respect for self and others -- behave professionally. - Integrity: Act with integrity and honesty. - Teamwork: Commit to and demonstrate teamwork. - Excellence: Ensure excellence, quality, and high ethical standards in conduct and performance. -TB testing and a Caregiver Background Check will be required at the time of employment. This position has been identified as a position of trust with access to vulnerable populations. The selected candidate will be required to pass an initial Caregiver Check to be eligible for employment under the Wisconsin Caregiver Law and then every four years. - The successful applicant will be responsible for ensuring eligibility for employment in the United States on or before the effective date of the appointment.

How to Apply:

To apply for this position, please click on the "Apply Now" button. You will be asked to upload a resume and cover letter, and provide three professional/supervisor references as a part of the application process. Please ensure that the resume and cover letter address how you meet the minimum/preferred qualifications for the position.

Jennifer Wilkie [email protected] 608-262-8025 Relay Access (WTRS): 7-1-1. See RELAY_SERVICE for further information.

Official Title:

Research Nurse(HS042)

Department(s):

A53-MEDICAL SCHOOL/CARBONE CANC CTR/CANC CTR

Employment Class:

Academic Staff-Renewable

Job Number:

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