conclusion and recommendation sample in case study

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How to write the conclusion of your case study

You worked on an amazing UX project. You documented every detail and deliverable and when the time came, you began to write a UX case study about it. In the case study, you highlighted how you worked through a Design Thinking process to get to the end result; so, can you stop there and now move on to the next thing? Well, no! There’s just one more bit left to finish up and make the perfect case study. So, get ready; we will now explore how you can write the perfect conclusion to wrap it all up and leave a lasting great impression.

Every start has an end – we’re not just repeating the famous quote here, because for case studies, a proper end is your last and final chance to leave a lasting great (at the very least, good) impression with whoever is reading your work (typically, recruiters!). Many junior UX designers often forget about the conclusion part of the case study, but this is a costly mistake to make. A well-written case study must end with an appropriate final section, in which you should summarize the key takeaways that you want others to remember about you and your work. Let’s see why.

Last impressions are just as important as first ones

We’ll go to some length here to convince you about the importance of last impressions, especially as we can understand the reason behind not wanting to pay very much attention to the end of your case study, after all the hard work you put into writing the process section. You are tired, and anyone who’s read your work should already have a good idea about your skills, anyway. Surely—you could be forgiven for thinking, at least—all that awesome material you put in the start and middle sections must have built up the momentum to take your work into orbit and make the recruiter’s last impression of you a lasting—and very good—one, and all you need to do now is take your leave. However, psychologist Saul McLeod (2008) explains how early work by experimental psychology pioneers Atkinson & Shriffin (1968) demonstrated that when humans are presented with information, they tend to remember the first and last elements and are more likely to forget the middle ones.

This is known as the “ serial position effect ” (more technically, the tendency to remember the first elements is known as the “ primacy effect ”, while the tendency to remember the last elements is known as the “ recency effect ”). Further work in human experiences discovered that the last few things we see or hear at the end of an experience can generate the most powerful memories that come back to us when we come across a situation or when we think about it. For example, let’s say you stayed in a hotel room that left a bit to be desired. Maybe the room was a little cramped, or the towels were not so soft. But if the receptionist, as you leave, shakes your hand warmly, smiles and thanks you sincerely for your custom, and goes out of his way to help you with your luggage, or to get you a taxi, you will remember that person’s kind demeanor more than you will remember the fact that the room facilities could be improved.

A good ending to your case study can help people forget some of the not-so-good points about your case study middle. For example, if you missed out a few crucial details but can demonstrate some truly interesting takeaways, they can always just ask you about these in an interview. Inversely, a bad ending leaves the recruiter with some doubt that will linger. Did this person learn nothing interesting from all this work? Did their work have no impact at all? Did they even write the case study themselves? A bad last impression can certainly undo much of the hard work you’ve put into writing the complicated middle part of your case study.

What to put in your case study conclusions

A case study ending is your opportunity to bring some closure to the story that you are writing. So, you can use it to mention the status of the project (e.g., is it ongoing or has it ended?) and then to demonstrate the impact that your work has had. By presenting some quantifiable results (e.g., data from end evaluations, analytics, key performance indicators ), you can demonstrate this impact. You can also discuss what you learned from this project, making you wiser than the next applicant – for example, something about a special category of users that the company might be interested in developing products for, or something that is cutting-edge and that advances the frontiers of science or practice.

As you can see, there are a few good ways in which you can end your case study. Next, we will outline four options that can be part of your ending: lessons learned, the impact of the project, reflections, and acknowledgements.

Lessons learned

A recruiter wants to see how you improve yourself by learning from the projects you work on. You can discuss interesting insights that you learned from user research or the evaluation of your designs – for example, surprising behaviors that you found out about the technology use in a group of users who are not typically considered to be big proponents of technology (e.g., older adults), or, perhaps, the reasons a particular design pattern didn’t work as well as expected under the context of your project.

Another thing you can discuss is your opinion on what the most difficult challenge of the project was, and comment on how you managed to overcome it. You can also discuss here things that you found out about yourself as a professional – for example, that you enjoyed taking on a UX role that you didn’t have previous experience with, or that you were able to overcome some personal limitations or build on your existing skills in a new way.

Impact of the project

Showing impact is always good. How did you measure the impact of your work? By using analytics, evaluation results, and even testimonials from your customers or users, or even your development or marketing team, you can demonstrate that your methodical approach to work brought about some positive change. Use before-after comparison data to demonstrate the extent of your impact. Verbatim positive quotes from your users or other project stakeholders are worth their weight (or rather, sentence length) in gold. Don’t go overboard, but mix and match the best evidence for the quality of your work to keep the end section brief and to the point.

Copyright holder: Andreas Komninos, Interaction Design Foundation. Copyright terms and license: CC BY-SA 3.0

User reviews from app stores are a great source of obtaining testimonials to include in your case studies. Overall app ratings and download volumes are also great bits of information to show impact.

An excerpt from a case study ending section. Here, text and accompanying charts are used to demonstrate the impact of the work done by the UX professional.

Reflections on your experiences

You can include some information that shows you have a clear understanding of how further work can build on the success of what you’ve already done. This demonstrates forward thinking and exploratory desire. Something else you can reflect on is your choices during the project. In every project, there might be things you could do differently or improve upon. But be aware that the natural question that follows such statements is this: “Well, so why haven’t you done it?”

Don’t shoot yourself in the foot by listing all the things you wish you could have done, but focus on what you’ve actually done and lay out future directions. For example, if you’ve done the user research in an ongoing project, don’t say, “ After all this user research, it would have been great to progress to a prototype, but it’s not yet done ”; instead, say, “ This user research is now enabling developers to quickly progress to the prototyping stage. ”

Acknowledgments

The end of the case study section is where you should put in your acknowledgments to any other members of your team, if this wasn’t a personal project. Your goal by doing so is to highlight your team spirit and humility in recognizing that great projects are most typically the result of collaboration . Be careful here, because it’s easy to make the waters muddy by not being explicit about what YOU did. So, for example, don’t write something like “ I couldn’t have done it without John X. and Jane Y. ”, but instead say this: “ My user research and prototype design fed into the development work carried out by John X. User testing was carried out by Jane Y., whose findings informed further re-design that I did on the prototypes. ”

What is a good length for a UX case study ending?

UX case studies must be kept short, and, when considering the length of your beginning, process and conclusion sections, it’s the beginning and the conclusion sections that should be the shortest of all. In some case studies, you can keep the ending to two or three short phrases. Other, longer case studies about more complex projects may require a slightly longer section.

Remember, though, that the end section is your chance for a last, short but impactful impression. If the hotel receptionist from our early example started to say goodbye and then went on and on to ask you about your experience, sharing with you the comments of other clients, or started talking to you about where you are going next, and why, and maybe if he had been there himself, started to tell you all about where to go and what to see, well… you get the point. Keep it short, sincere and focused. And certainly, don’t try to make the project sound more important than it was. Recruiters are not stupid – they’ve been there and done that, so they know.

Putting it all together

In the example below, we will show how you can address the points above using text. We are going to focus on the three main questions here, so you can see an example of this in action, for a longer case study.

An example ending section for a longer case study, addressing all aspects: Lessons, impact, reflection and acknowledgments.

Here is how we might structure the text for a shorter version of the same case study, focusing on the bare essentials:

An example ending section for a shorter case study, addressing the most critical aspects: Lessons, impact and reflection. Acknowledgments are being sacrificed for the sake of brevity here, but perhaps that’s OK – you might mention it in the middle part of the case study.

The Take Away

The end part of your case study needs as much care and attention as the rest of it does. You shouldn’t neglect it just because it’s the last thing in the case study. It’s not hard work if you know the basics, and here, we’ve given you the pointers you need to ensure that you don’t miss out anything important. The end part of the case study should leave your recruiters with a good (hopefully, very good) last impression of you and your work, so give it the thorough consideration it needs, to ensure it doesn’t undo all the hard work you’ve put into the case study.

References & Where to Learn More

Copyright holder: Andrew Hurley, Flickr. Copyright terms and license: CC BY-SA 2.0

Atkinson, R. C., & Shiffrin, R. M. (1968). Chapter: Human memory : A proposed system and its control processes. In Spence, K. W., & Spence, J. T. The psychology of learning and motivation (Volume 2). New York: Academic Press. pp. 89–195.

McLeod, S. (2008). Serial Position Effect

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How To Make Recommendation in Case Study (With Examples)

After analyzing your case study’s problem and suggesting possible courses of action , you’re now ready to conclude it on a high note. 

But first, you need to write your recommendation to address the problem. In this article, we will guide you on how to make a recommendation in a case study. 

Table of Contents

What is recommendation in case study, what is the purpose of recommendation in the case study, 1. review your case study’s problem, 2. assess your case study’s alternative courses of action, 3. pick your case study’s best alternative course of action, 4. explain in detail why you recommend your preferred course of action, examples of recommendations in case study, tips and warnings.

The Recommendation details your most preferred solution for your case study’s problem.

After identifying and analyzing the problem, your next step is to suggest potential solutions. You did this in the Alternative Courses of Action (ACA) section. Once you’re done writing your ACAs, you need to pick which among these ACAs is the best. The chosen course of action will be the one you’re writing in the recommendation section. 

The Recommendation portion also provides a thorough justification for selecting your most preferred solution. 

Notice how a recommendation in a case study differs from a recommendation in a research paper . In the latter, the recommendation tells your reader some potential studies that can be performed in the future to support your findings or to explore factors that you’re unable to cover. 

Your main goal in writing a case study is not only to understand the case at hand but also to think of a feasible solution. However, there are multiple ways to approach an issue. Since it’s impossible to implement all these solutions at once, you only need to pick the best one. 

The Recommendation portion tells the readers which among the potential solutions is best to implement given the constraints of an organization or business. This section allows you to introduce, defend, and explain this optimal solution. 

How To Write Recommendation in Case Study

You cannot recommend a solution if you are unable to grasp your case study’s issue. Make sure that you’re aware of the problem as well as the viewpoint from which you want to analyze it . 

Once you’ve fully grasped your case study’s problem, it’s time to suggest some feasible solutions to address it. A separate section of your manuscript called the Alternative Courses of Action (ACA) is dedicated to discussing these potential solutions. 

Afterward, you need to evaluate each ACA by identifying its respective advantages and disadvantages. 

After evaluating each proposed ACA, pick the one you’ll recommend to address the problem. All alternatives have their pros and cons so you must use your discretion in picking the best among these ACAs.

To help you decide which ACA to pick, here are some factors to consider:

• Realistic : The organization must have sufficient knowledge, expertise, resources, and manpower to execute the recommended solution. 
• Economical: The recommended solution must be cost-effective.
• Legal: The recommended solution must adhere to applicable laws.
• Ethical: The recommended solution must not have moral repercussions. 
• Timely: The recommended solution can be executed within the expected timeframe. 

You may also use a decision matrix to assist you in picking the best ACA 1 .  This matrix allows you to rank the ACAs based on your criteria. Please refer to our examples in the next section for an example of a Recommendation formed using a decision matrix. 

Provide your justifications for why you recommend your preferred solution. You can also explain why other alternatives are not chosen 2 .  

To help you understand how to make recommendations in a case study, let’s take a look at some examples below.

Case Study Problem : Lemongate Hotel is facing an overwhelming increase in the number of reservations due to a sudden implementation of a Local Government policy that boosts the city’s tourism. Although Lemongate Hotel has a sufficient area to accommodate the influx of tourists, the management is wary of the potential decline in the hotel’s quality of service while striving to meet the sudden increase in reservations. 

Alternative Courses of Action:

• ACA 1: Relax hiring qualifications to employ more hotel employees to ensure that sufficient human resources can provide quality hotel service
• ACA 2: Increase hotel reservation fees and other costs as a response to the influx of tourists demanding hotel accommodation
• ACA 3: Reduce privileges and hotel services enjoyed by each customer so that hotel employees will not be overwhelmed by the increase in accommodations.

Recommendation: 

Upon analysis of the problem, it is recommended to implement ACA 1. Among all suggested ACAs, this option is the easiest to execute with the minimal cost required. It will not also impact potential profits and customers’ satisfaction with hotel service.

Meanwhile, implementing ACA 2 might discourage customers from making reservations due to higher fees and look for other hotels as substitutes. It is also not recommended to do ACA 3 because reducing hotel services and privileges offered to customers might harm the hotel’s public reputation in the long run. 

The first paragraph of our sample recommendation specifies what ACA is best to implement and why.

Meanwhile, the succeeding paragraphs explain that ACA 2 and ACA 3 are not optimal solutions due to some of their limitations and potential negative impacts on the organization. 

Example 2 (with Decision Matrix)

Case Study: Last week, Pristine Footwear released its newest sneakers model for women – “Flightless.” However, the management noticed that “Flightless” had a mediocre sales performance in the previous week. For this reason, “Flightless” might be pulled out in the next few months.  The management must decide on the fate of “Flightless” with Pristine Footwear’s financial performance in mind. 

• ACA 1: Revamp “Flightless” marketing by hiring celebrities/social media influencers to promote the product
• ACA 2: Improve the “Flightless” current model by tweaking some features to fit current style trends
• ACA 3: Sell “Flightless” at a lower price to encourage more customers
• ACA 4: Stop production of “Flightless” after a couple of weeks to cut losses

Decision Matrix

Recommendation

Based on the decision matrix above 3 , the best course of action that Pristine Wear, Inc. must employ is ACA 3 or selling “Flightless” shoes at lower prices to encourage more customers. This solution can be implemented immediately without the need for an excessive amount of financial resources. Since lower prices entice customers to purchase more, “Flightless” sales might perform better given a reduction in its price.

In this example, the recommendation was formed with the help of a decision matrix. Each ACA was given a score of between 1 – 4 for each criterion. Note that the criterion used depends on the priorities of an organization, so there’s no standardized way to make this matrix. 

Meanwhile, the recommendation we’ve made here consists of only one paragraph. Although the matrix already revealed that ACA 3 tops the selection, we still provided a clear explanation of why it is the best. 

• Recommend with persuasion 4 . You may use data and statistics to back up your claim. Another option is to show that your preferred solution fits your theoretical knowledge about the case. For instance, if your recommendation involves reducing prices to entice customers to buy higher quantities of your products, you may invoke the “law of demand” 5 as a theoretical foundation of your recommendation. 
• Be prepared to make an implementation plan. Some case study formats require an implementation plan integrated with your recommendation. Basically, the implementation plan provides a thorough guide on how to execute your chosen solution (e.g., a step-by-step plan with a schedule).
• Manalili, K. (2021 – 2022). Selection of Best Applicant (Unpublished master’s thesis). Bulacan Agricultural State College. Retrieved September 23, 2022, from https://www.studocu.com/ph/document/bulacan-agricultural-state-college/business-administration/case-study-human-rights/19062233.
• How to Analyze a Case Study. (n.d.). Retrieved September 23, 2022, from https://wps.prenhall.com/bp_laudon_essbus_7/48/12303/3149605.cw/content/index.html
• Nguyen, C. (2022, April 13). How to Use a Decision Matrix to Assist Business Decision Making. Retrieved September 23, 2022, from https://venngage.com/blog/decision-matrix/
• Case Study Analysis: Examples + How-to Guide & Writing Tips. (n.d.). Retrieved September 23, 2022, from https://custom-writing.org/blog/great-case-study-analysis
• Hayes, A. (2022, January O8). Law of demand. Retrieved September 23, 2022, from https://www.investopedia.com/terms/l/lawofdemand.asp

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Jewel Kyle Fabula

Jewel Kyle Fabula is a Bachelor of Science in Economics student at the University of the Philippines Diliman. His passion for learning mathematics developed as he competed in some mathematics competitions during his Junior High School years. He loves cats, playing video games, and listening to music.

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How to Write a Conclusion for Research Papers (with Examples)

The conclusion of a research paper is a crucial section that plays a significant role in the overall impact and effectiveness of your research paper. However, this is also the section that typically receives less attention compared to the introduction and the body of the paper. The conclusion serves to provide a concise summary of the key findings, their significance, their implications, and a sense of closure to the study. Discussing how can the findings be applied in real-world scenarios or inform policy, practice, or decision-making is especially valuable to practitioners and policymakers. The research paper conclusion also provides researchers with clear insights and valuable information for their own work, which they can then build on and contribute to the advancement of knowledge in the field.

The research paper conclusion should explain the significance of your findings within the broader context of your field. It restates how your results contribute to the existing body of knowledge and whether they confirm or challenge existing theories or hypotheses. Also, by identifying unanswered questions or areas requiring further investigation, your awareness of the broader research landscape can be demonstrated.

Remember to tailor the research paper conclusion to the specific needs and interests of your intended audience, which may include researchers, practitioners, policymakers, or a combination of these.

Table of Contents

What is a conclusion in a research paper, summarizing conclusion, editorial conclusion, externalizing conclusion, importance of a good research paper conclusion, how to write a conclusion for your research paper, research paper conclusion examples.

• How to write a research paper conclusion with Paperpal? 

Frequently Asked Questions

A conclusion in a research paper is the final section where you summarize and wrap up your research, presenting the key findings and insights derived from your study. The research paper conclusion is not the place to introduce new information or data that was not discussed in the main body of the paper. When working on how to conclude a research paper, remember to stick to summarizing and interpreting existing content. The research paper conclusion serves the following purposes: 1

• Warn readers of the possible consequences of not attending to the problem.
• Recommend specific course(s) of action.
• Restate key ideas to drive home the ultimate point of your research paper.
• Provide a “take-home” message that you want the readers to remember about your study.

Types of conclusions for research papers

In research papers, the conclusion provides closure to the reader. The type of research paper conclusion you choose depends on the nature of your study, your goals, and your target audience. I provide you with three common types of conclusions:

A summarizing conclusion is the most common type of conclusion in research papers. It involves summarizing the main points, reiterating the research question, and restating the significance of the findings. This common type of research paper conclusion is used across different disciplines.

An editorial conclusion is less common but can be used in research papers that are focused on proposing or advocating for a particular viewpoint or policy. It involves presenting a strong editorial or opinion based on the research findings and offering recommendations or calls to action.

An externalizing conclusion is a type of conclusion that extends the research beyond the scope of the paper by suggesting potential future research directions or discussing the broader implications of the findings. This type of conclusion is often used in more theoretical or exploratory research papers.

Align your conclusion’s tone with the rest of your research paper. Start Writing with Paperpal Now!  

The conclusion in a research paper serves several important purposes:

• Offers Implications and Recommendations : Your research paper conclusion is an excellent place to discuss the broader implications of your research and suggest potential areas for further study. It’s also an opportunity to offer practical recommendations based on your findings.
• Provides Closure : A good research paper conclusion provides a sense of closure to your paper. It should leave the reader with a feeling that they have reached the end of a well-structured and thought-provoking research project.
• Leaves a Lasting Impression : Writing a well-crafted research paper conclusion leaves a lasting impression on your readers. It’s your final opportunity to leave them with a new idea, a call to action, or a memorable quote.

Writing a strong conclusion for your research paper is essential to leave a lasting impression on your readers. Here’s a step-by-step process to help you create and know what to put in the conclusion of a research paper: 2

• Research Statement : Begin your research paper conclusion by restating your research statement. This reminds the reader of the main point you’ve been trying to prove throughout your paper. Keep it concise and clear.
• Key Points : Summarize the main arguments and key points you’ve made in your paper. Avoid introducing new information in the research paper conclusion. Instead, provide a concise overview of what you’ve discussed in the body of your paper.
• Address the Research Questions : If your research paper is based on specific research questions or hypotheses, briefly address whether you’ve answered them or achieved your research goals. Discuss the significance of your findings in this context.
• Significance : Highlight the importance of your research and its relevance in the broader context. Explain why your findings matter and how they contribute to the existing knowledge in your field.
• Implications : Explore the practical or theoretical implications of your research. How might your findings impact future research, policy, or real-world applications? Consider the “so what?” question.
• Future Research : Offer suggestions for future research in your area. What questions or aspects remain unanswered or warrant further investigation? This shows that your work opens the door for future exploration.
• Closing Thought : Conclude your research paper conclusion with a thought-provoking or memorable statement. This can leave a lasting impression on your readers and wrap up your paper effectively. Avoid introducing new information or arguments here.
• Proofread and Revise : Carefully proofread your conclusion for grammar, spelling, and clarity. Ensure that your ideas flow smoothly and that your conclusion is coherent and well-structured.

Write your research paper conclusion 2x faster with Paperpal. Try it now!

Remember that a well-crafted research paper conclusion is a reflection of the strength of your research and your ability to communicate its significance effectively. It should leave a lasting impression on your readers and tie together all the threads of your paper. Now you know how to start the conclusion of a research paper and what elements to include to make it impactful, let’s look at a research paper conclusion sample.

How to write a research paper conclusion with Paperpal?

A research paper conclusion is not just a summary of your study, but a synthesis of the key findings that ties the research together and places it in a broader context. A research paper conclusion should be concise, typically around one paragraph in length. However, some complex topics may require a longer conclusion to ensure the reader is left with a clear understanding of the study’s significance. Paperpal, an AI writing assistant trusted by over 800,000 academics globally, can help you write a well-structured conclusion for your research paper. 

• Sign Up or Log In: Create a new Paperpal account or login with your details.  
• Navigate to Features : Once logged in, head over to the features’ side navigation pane. Click on Templates and you’ll find a suite of generative AI features to help you write better, faster.  
• Generate an outline: Under Templates, select ‘Outlines’. Choose ‘Research article’ as your document type.  
• Select your section: Since you’re focusing on the conclusion, select this section when prompted.  
• Choose your field of study: Identifying your field of study allows Paperpal to provide more targeted suggestions, ensuring the relevance of your conclusion to your specific area of research. 
• Provide a brief description of your study: Enter details about your research topic and findings. This information helps Paperpal generate a tailored outline that aligns with your paper’s content. 
• Generate the conclusion outline: After entering all necessary details, click on ‘generate’. Paperpal will then create a structured outline for your conclusion, to help you start writing and build upon the outline.  
• Write your conclusion: Use the generated outline to build your conclusion. The outline serves as a guide, ensuring you cover all critical aspects of a strong conclusion, from summarizing key findings to highlighting the research’s implications. 
• Refine and enhance: Paperpal’s ‘Make Academic’ feature can be particularly useful in the final stages. Select any paragraph of your conclusion and use this feature to elevate the academic tone, ensuring your writing is aligned to the academic journal standards. 

By following these steps, Paperpal not only simplifies the process of writing a research paper conclusion but also ensures it is impactful, concise, and aligned with academic standards. Sign up with Paperpal today and write your research paper conclusion 2x faster .  

The research paper conclusion is a crucial part of your paper as it provides the final opportunity to leave a strong impression on your readers. In the research paper conclusion, summarize the main points of your research paper by restating your research statement, highlighting the most important findings, addressing the research questions or objectives, explaining the broader context of the study, discussing the significance of your findings, providing recommendations if applicable, and emphasizing the takeaway message. The main purpose of the conclusion is to remind the reader of the main point or argument of your paper and to provide a clear and concise summary of the key findings and their implications. All these elements should feature on your list of what to put in the conclusion of a research paper to create a strong final statement for your work.

A strong conclusion is a critical component of a research paper, as it provides an opportunity to wrap up your arguments, reiterate your main points, and leave a lasting impression on your readers. Here are the key elements of a strong research paper conclusion: 1. Conciseness : A research paper conclusion should be concise and to the point. It should not introduce new information or ideas that were not discussed in the body of the paper. 2. Summarization : The research paper conclusion should be comprehensive enough to give the reader a clear understanding of the research’s main contributions. 3 . Relevance : Ensure that the information included in the research paper conclusion is directly relevant to the research paper’s main topic and objectives; avoid unnecessary details. 4 . Connection to the Introduction : A well-structured research paper conclusion often revisits the key points made in the introduction and shows how the research has addressed the initial questions or objectives. 5. Emphasis : Highlight the significance and implications of your research. Why is your study important? What are the broader implications or applications of your findings? 6 . Call to Action : Include a call to action or a recommendation for future research or action based on your findings.

The length of a research paper conclusion can vary depending on several factors, including the overall length of the paper, the complexity of the research, and the specific journal requirements. While there is no strict rule for the length of a conclusion, but it’s generally advisable to keep it relatively short. A typical research paper conclusion might be around 5-10% of the paper’s total length. For example, if your paper is 10 pages long, the conclusion might be roughly half a page to one page in length.

In general, you do not need to include citations in the research paper conclusion. Citations are typically reserved for the body of the paper to support your arguments and provide evidence for your claims. However, there may be some exceptions to this rule: 1. If you are drawing a direct quote or paraphrasing a specific source in your research paper conclusion, you should include a citation to give proper credit to the original author. 2. If your conclusion refers to or discusses specific research, data, or sources that are crucial to the overall argument, citations can be included to reinforce your conclusion’s validity.

The conclusion of a research paper serves several important purposes: 1. Summarize the Key Points 2. Reinforce the Main Argument 3. Provide Closure 4. Offer Insights or Implications 5. Engage the Reader. 6. Reflect on Limitations

Remember that the primary purpose of the research paper conclusion is to leave a lasting impression on the reader, reinforcing the key points and providing closure to your research. It’s often the last part of the paper that the reader will see, so it should be strong and well-crafted.

• Makar, G., Foltz, C., Lendner, M., & Vaccaro, A. R. (2018). How to write effective discussion and conclusion sections. Clinical spine surgery, 31(8), 345-346.
• Bunton, D. (2005). The structure of PhD conclusion chapters.  Journal of English for academic purposes ,  4 (3), 207-224.

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How to Write Effective Case Study Conclusions

Table of Contents

Not many people realize that the conclusion is vital to writing your case study. It should summarize the entire study, clarify all the research points, and focus on a few key takeaways.

There are several ways how to write case study conclusion . And we’re here to guide you with some easy and effective steps.

A good conclusion is interesting and captures the essence of your case. It needs to reflect your information and help the reader adopt your conclusion and act on it. Keep reading to learn how to do just that.

Importance of Your Case Study Conclusion

Your conclusion is an opportunity for you to summarize your findings and highlight what this study has taught you.

It should also summarize and draw out the main points you’ve discussed and reinforce the importance of your work. Remember, your last impression needs to be just as good as your first. You want to leave readers with something to think about or act on.

Types of Case Studies

Before we proceed on  how to write case study conclusion , let’s take a brief look at the different types of case studies.

There are different types of case studies depending on how they are structured, what is the target audience, and the research methodology used. And your conclusion may vary depending on the nature of the case study.

Some of the most common case studies are:

• Historical:  Historical events have a multitude of sources offering different perspectives. These perspectives can be applied, compared, and thoroughly analyzed in the modern world.
• Problem-oriented:  This type of case study is used for solving problems. You can use theoretical situations where you immerse yourself in a situation. Through this, you can thoroughly examine a problem and find ways to resolve it.
• Cumulative:  In a cumulative study, you gather information and offer comparisons. An example of this is a business case study that tells people about a product’s value.
• Critical:  Critical case studies focus on exploring the causes and effects of a particular situation. To do this, you can have varying amounts of research and various interviews.
• Illustrative:  In this case study, certain events are described, as well as the lessons learned.

How to Write Case Study Conclusion Effectively

Writing your conclusion doesn’t need to be complicated. Follow these steps to help you get started on an effective conclusion.

1. Inform the reader precisely why your case study and your findings are relevant

Your conclusion is where you point out the significance of your study. You can cite a specific case in your work and explain how it applies to other relevant cases.

2. Restate your thesis and your main findings

Remind your readers of the thesis statement you made in your introduction but don’t just copy it directly. Also, make sure to mention your main findings to back up your thesis.

3. Give a summary of previous case studies you reviewed

What did you discover that was different about your case? How was previous research helpful? Include this in your conclusion so readers can understand your work and how it contributes to expanding current knowledge.

4. End with recommendations

Wrap up your paper by explaining how your case study and findings could form part of future research on the topic. You can also express your recommendations by commenting on how certain studies, programs, or policies could be improved.

Make sure everything you write in your conclusion section is convincing enough to tell the reader that your case is an effective solution. And if the purpose of your case is complicated, make sure to sum it up in point form. This will help the reader review the case again before approaching the conclusion.

How Long Should Your Conclusion Be?

The length of your conclusion may vary depending on whether you’re writing a thesis or a dissertation. At least 5-9 percent of your overall word count should be dedicated to your conclusion.

Often, empirical scientific studies have brief conclusions describing the main findings and recommendations for future research. On the other hand, humanities topics or systematic reviews may require more space to conclude their analysis. They will need to integrate all the previous sections into an overall argument.

Wrapping Up

Your conclusion is an opportunity to translate and amplify the information you have put in the body of the paper.

More importantly, it is an opportunity to leave a lasting positive impression . Make the right impression by following these quick steps on  how to write case study conclusion  effectively.

Abir Ghenaiet

Abir is a data analyst and researcher. Among her interests are artificial intelligence, machine learning, and natural language processing. As a humanitarian and educator, she actively supports women in tech and promotes diversity.

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• How to Write Discussions and Conclusions

The discussion section contains the results and outcomes of a study. An effective discussion informs readers what can be learned from your experiment and provides context for the results.

What makes an effective discussion?

When you’re ready to write your discussion, you’ve already introduced the purpose of your study and provided an in-depth description of the methodology. The discussion informs readers about the larger implications of your study based on the results. Highlighting these implications while not overstating the findings can be challenging, especially when you’re submitting to a journal that selects articles based on novelty or potential impact. Regardless of what journal you are submitting to, the discussion section always serves the same purpose: concluding what your study results actually mean.

A successful discussion section puts your findings in context. It should include:

• the results of your research,
• a discussion of related research, and
• a comparison between your results and initial hypothesis.

Tip: Not all journals share the same naming conventions.

You can apply the advice in this article to the conclusion, results or discussion sections of your manuscript.

Our Early Career Researcher community tells us that the conclusion is often considered the most difficult aspect of a manuscript to write. To help, this guide provides questions to ask yourself, a basic structure to model your discussion off of and examples from published manuscripts. 

Questions to ask yourself:

• Was my hypothesis correct?
• If my hypothesis is partially correct or entirely different, what can be learned from the results? 
• How do the conclusions reshape or add onto the existing knowledge in the field? What does previous research say about the topic? 
• Why are the results important or relevant to your audience? Do they add further evidence to a scientific consensus or disprove prior studies? 
• How can future research build on these observations? What are the key experiments that must be done? 
• What is the “take-home” message you want your reader to leave with?

How to structure a discussion

Trying to fit a complete discussion into a single paragraph can add unnecessary stress to the writing process. If possible, you’ll want to give yourself two or three paragraphs to give the reader a comprehensive understanding of your study as a whole. Here’s one way to structure an effective discussion:

Writing Tips

While the above sections can help you brainstorm and structure your discussion, there are many common mistakes that writers revert to when having difficulties with their paper. Writing a discussion can be a delicate balance between summarizing your results, providing proper context for your research and avoiding introducing new information. Remember that your paper should be both confident and honest about the results! 

• Read the journal’s guidelines on the discussion and conclusion sections. If possible, learn about the guidelines before writing the discussion to ensure you’re writing to meet their expectations. 
• Begin with a clear statement of the principal findings. This will reinforce the main take-away for the reader and set up the rest of the discussion. 
• Explain why the outcomes of your study are important to the reader. Discuss the implications of your findings realistically based on previous literature, highlighting both the strengths and limitations of the research. 
• State whether the results prove or disprove your hypothesis. If your hypothesis was disproved, what might be the reasons? 
• Introduce new or expanded ways to think about the research question. Indicate what next steps can be taken to further pursue any unresolved questions. 
• If dealing with a contemporary or ongoing problem, such as climate change, discuss possible consequences if the problem is avoided. 
• Be concise. Adding unnecessary detail can distract from the main findings. 

Don’t

• Rewrite your abstract. Statements with “we investigated” or “we studied” generally do not belong in the discussion. 
• Include new arguments or evidence not previously discussed. Necessary information and evidence should be introduced in the main body of the paper. 
• Apologize. Even if your research contains significant limitations, don’t undermine your authority by including statements that doubt your methodology or execution. 
• Shy away from speaking on limitations or negative results. Including limitations and negative results will give readers a complete understanding of the presented research. Potential limitations include sources of potential bias, threats to internal or external validity, barriers to implementing an intervention and other issues inherent to the study design. 
• Overstate the importance of your findings. Making grand statements about how a study will fully resolve large questions can lead readers to doubt the success of the research. 

Snippets of Effective Discussions:

Consumer-based actions to reduce plastic pollution in rivers: A multi-criteria decision analysis approach

Identifying reliable indicators of fitness in polar bears

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How to Successfully Conclude a Case Study

Knowing how to successfully conclude a case study is one of the most important parts of every case interview. A strong conclusion shows how well you summarize the entire case solution into a couple of points. In addition, it proves that you can successfully back up your arguments with both quantitative and qualitative facts. It’s also the very last point of the case, thus the point clients remember the most. 

How to Successfully Conclude a Case Study - Best Practice Approaches 

Take approximately 30 seconds before concluding the case, and use this time to jot down key messages you want to touch on during your recommendation. You want to have your ideas sorted out in advance so that you speak clearly and concisely, covering each point without referring back to your notes. 

Practice the art of the elevator pitch

Ideally, your final recommendation should not exceed more than one minute. It is a way to mimic day-to-day interactions with our clients when we are asked to give them key pointers in a short summary. 

Answer first and answer focused

As you will see more in detail with Prepmatter cases, in many case types, you should start with the answer. However, in certain case types where the client has a business problem yet to be diagnosed (e.g., competitive response strategy, profitability, operations), it’s best to start with your diagnosis and then provide recovery solutions. 

Allocate time correctly

Make sure to allocate most of your time to the delivery of a solution and its supporting evidence. Some candidates spend half - if not more - of their time in delivering risks and next steps, which dilutes the key messages in the recommendation. Conclude the case in the following structure: 

• Recommendation: Give a one-sentence action-oriented recommendation. 
• First supporting fact with figures (quantitative) 
• Second supporting fact with figures (quantitative)
• Third supporting fact (qualitative)
• Risks: Comment on the potential risks assessed during the case. Try to mention them in a way supporting your conclusion. 
• Next steps: Provide direction on how they should act going forward based on the recommendation.

Example of a Strong Conclusion

• I suggest the client should go ahead with this investment and enter the cosmetics market with their new product.
• With this investment, the client can make an $800M profit over the next three years, which is higher than our objective of $600M. 
• The cosmetics market is expected to grow at a 9% annual growth rate over the next 10 years, promising sustainable value in the long term. 
• We can create synergies by combining our back-end operations with our existing business. 
• Risks: There is a regulatory risk given that the authorities increase their health restrictions related to cosmetics products. The client should make sure that they spend additional effort to comply with all regulations. 
• Next steps: As the next step, I suggest the client design a detailed production plan for the new product. 

How to Practice Case Conclusions

There are various ways to practice concluding a case. Practice with the Prepmatter cases or any other case you may have. You can change the numbers in the case to create hypothetical facts and draw a new conclusion. By doing so, you can also change the recommendation if the numbers change significantly. For instance, if you change the 3-year profits to $400M from $800M in the example above, the recommendation would change from ‘Go’ to ‘No-go’. 

Knowing how to successfully conclude a case study is a critical part of each case interview, so we recommend you set aside specific time to review it with your coach or case partner. Take time to solve as many cases as possible to improve how well you summarize, support, and present your conclusion.

Writing the parts of scientific reports

22 Writing the conclusion & recommendations

There are probably some overlaps between the Conclusion and the Discussion section. Nevertheless, this section gives you the opportunity to highlight the most important points in your report, and is sometimes the only section read. Think about what your research/ study has achieved, and the most important findings and ideas you want the reader to know. As all studies have limitations also think about what you were not able to cover (this shows that you are able to evaluate your own work objectively).

Possible structure of this section:

Use present perfect to sum up/ evaluate:

This study has explored/ has attempted …

Use past tense to state what your aim was and to refer to actions you carried out:

• This study was intended to analyse …
• The aim of this study was to …

Use present tense to evaluate your study and to state the generalizations and implications that you draw from your findings.

• The results add to the knowledge of …
• These findings s uggest that …

You can either use present tense or past tense to summarize your results.

• The findings reveal …
• It was found that …

Achievements of this study (positive)

• This study provides evidence that …
• This work has contributed to a number of key issues in the field such as …

Limitations of the study (negative)

• Several limitations should be noted. First …

Combine positive and negative remarks to give a balanced assessment:

• Although this research is somewhat limited in scope, its findings can provide a basis for future studies.
• Despite the limitations, findings from the present study can help us understand …

Use more cautious language (modal verbs may, can, could)

• There are a number of possible extensions of this research …
• The findings suggest the possibility for future research on …
• These results may be important for future studies on …
• Examining a wider context could/ would lead …

Or indicate that future research is needed

• There is still a need for future research to determine …
• Further studies should be undertaken to discover…
• It would be worthwhile to investigate …

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• How to Write Recommendations in Research | Examples & Tips

How to Write Recommendations in Research | Examples & Tips

Published on 15 September 2022 by Tegan George .

Recommendations in research are a crucial component of your discussion section and the conclusion of your thesis , dissertation , or research paper .

As you conduct your research and analyse the data you collected , perhaps there are ideas or results that don’t quite fit the scope of your research topic . Or, maybe your results suggest that there are further implications of your results or the causal relationships between previously-studied variables than covered in extant research.

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Table of contents

What should recommendations look like, building your research recommendation, how should your recommendations be written, recommendation in research example, frequently asked questions about recommendations.

Recommendations for future research should be:

• Concrete and specific
• Supported with a clear rationale
• Directly connected to your research

Overall, strive to highlight ways other researchers can reproduce or replicate your results to draw further conclusions, and suggest different directions that future research can take, if applicable.

Relatedly, when making these recommendations, avoid:

• Undermining your own work, but rather offer suggestions on how future studies can build upon it
• Suggesting recommendations actually needed to complete your argument, but rather ensure that your research stands alone on its own merits
• Using recommendations as a place for self-criticism, but rather as a natural extension point for your work

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There are many different ways to frame recommendations, but the easiest is perhaps to follow the formula of research question   conclusion  recommendation. Here’s an example.

Conclusion An important condition for controlling many social skills is mastering language. If children have a better command of language, they can express themselves better and are better able to understand their peers. Opportunities to practice social skills are thus dependent on the development of language skills.

As a rule of thumb, try to limit yourself to only the most relevant future recommendations: ones that stem directly from your work. While you can have multiple recommendations for each research conclusion, it is also acceptable to have one recommendation that is connected to more than one conclusion.

These recommendations should be targeted at your audience, specifically toward peers or colleagues in your field that work on similar topics to yours. They can flow directly from any limitations you found while conducting your work, offering concrete and actionable possibilities for how future research can build on anything that your own work was unable to address at the time of your writing.

See below for a full research recommendation example that you can use as a template to write your own.

The current study can be interpreted as a first step in the research on COPD speech characteristics. However, the results of this study should be treated with caution due to the small sample size and the lack of details regarding the participants’ characteristics.

Future research could further examine the differences in speech characteristics between exacerbated COPD patients, stable COPD patients, and healthy controls. It could also contribute to a deeper understanding of the acoustic measurements suitable for e-health measurements.

While it may be tempting to present new arguments or evidence in your thesis or disseration conclusion , especially if you have a particularly striking argument you’d like to finish your analysis with, you shouldn’t. Theses and dissertations follow a more formal structure than this.

All your findings and arguments should be presented in the body of the text (more specifically in the discussion section and results section .) The conclusion is meant to summarize and reflect on the evidence and arguments you have already presented, not introduce new ones.

The conclusion of your thesis or dissertation should include the following:

• A restatement of your research question
• A summary of your key arguments and/or results
• A short discussion of the implications of your research

For a stronger dissertation conclusion , avoid including:

• Generic concluding phrases (e.g. “In conclusion…”)
• Weak statements that undermine your argument (e.g. “There are good points on both sides of this issue.”)

Your conclusion should leave the reader with a strong, decisive impression of your work.

In a thesis or dissertation, the discussion is an in-depth exploration of the results, going into detail about the meaning of your findings and citing relevant sources to put them in context.

The conclusion is more shorter and more general: it concisely answers your main research question and makes recommendations based on your overall findings.

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Case Study Conclusion

The end is sometimes the most visible piece of academic writing. The conclusion of the case study is an ignored portion. Several students make case study research papers every year on the demand of their tutors. But, very few of them realize the importance of every segment of it. From the introduction to the case study conclusion, every single thing matters. As it’s a matter of your future academic success, it is equally beneficial for the students to craft valuable endings for their case studies.

Students may question themselves about, what makes a brilliant conclusion? Well, there are plenty of rules that should be applied while making one. For example, there are a few things to be kept in mind for writing the introductions. Similarly, extensive research is required to make an impactful conclusion for a case study.

Importance OF A Conclusion In The Case Study For A Student

It’s a years-long pattern that the last part of any content gets neglected. The reasons are quite clear, either you lose interest in your topic, or you want to finish it in a hurry. But whatever the reason it is, it’s not ideal to ignore the end of your case study solutions writing. Various elements define the importance of the concluding part.

The ending is the most read portion of the content as it summarizes all the vital points of the introduction of your case study. So if you have not paid much attention to your conclusions, there are high chance that your case study will not look impressive.

The Common Sample OF Conclusion And Recommendation In The Case Study

Students can feasibly go through our site to get samples of the conclusion of a case study. However, the most common things you can find in a case study sample are the proper solutions to your argued problems. Not to forget the requirements of the deep analysis on how to overcome them.

A good case study is nothing without the relevant samples and recommendations. Hence, it’s the most crucial part of the writings to list the proper recommendations for your tutors. Students are advised that all of their suggestions must include specific reports of all the emerging limitations. They can address all of the issues with the possible solutions to them that would be helpful for future work.

It doesn’t matter if you are concluding a long report or a short one. The recommendations should be listed in pointers to avoid any confusion and add more to the clarity.

What Case Study Conclusions Should Look Like?

Your conclusion is the most integral part of your research papers. If a good conclusion has been provided to the case study, there are high chances that your not-so-good point in the middle of the starting sections gets blurred. The conclusion part of the case study that brings closure to your story is the reformed way. All of your researched data can have more impact if the ending part of your case study states the solutions to the key issues.

Example OF The Case Studies Conclusion

Students can list what they have learned from this particular topic in their conclusion. It can make you wiser in comparison to the next applicant. For example, you can discuss any special category of the users related to the company you are conducting a case study on. You can highlight the new products which they are interested in launching. You can also discuss something that is cutting-edge and advances the boundaries of practice or science.

As you can see, there are various ways by which you can create a lasting impact on your conclusions.

Get Our Help To Write An Impressive Conclusion For Your Case Study

Writing an excellent case study is not an easy task to accomplish. Moreover, its different sections from the beginning to the conclusion demand immense intensity and research. But, we assure our students that our case study writers can deliver quality case studies to you. They are experts in creating unique content. Hence, you can freely rely on our case study services to attain the utmost satisfaction.

How Do You Write A Conclusion?

The conclusion of a case study comprises of the following important steps:

1. Look out for the logical connections.

2. Make sure your conclusion has a direct link to your introduction.

3. Keep the basic logic in mind.

4. Encourage the reader to draw their own conclusions.

5. Provide recommendations.

6. Conclusions should be definite.

7. The recommendations should directly adhere to your conclusion.

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Health Care Comes Home: The Human Factors (2011)

Chapter: 7 conclusions and recommendations.

7 Conclusions and Recommendations

Health care is moving into the home increasingly often and involving a mixture of people, a variety of tasks, and a broad diversity of devices and technologies; it is also occurring in a range of residential environments. The factors driving this migration include the rising costs of providing health care; the growing numbers of older adults; the increasing prevalence of chronic disease; improved survival rates of various diseases, injuries, and other conditions (including those of fragile newborns); large numbers of veterans returning from war with serious injuries; and a wide range of technological innovations. The health care that results varies considerably in its safety, effectiveness, and efficiency, as well as its quality and cost.

The committee was charged with examining this major trend in health care delivery and resulting challenges from only one of many perspectives: the study of human factors. From the outset it was clear that the dramatic and evolving change in health care practice and policies presents a broad array of opportunities and problems. Consequently the committee endeavored to maintain focus specifically on how using the human factors approach can provide solutions that support maximizing the safety and quality of health care delivered in the home while empowering both care recipients and caregivers in the effort.

The conclusions and recommendations presented below reflect the most critical steps that the committee thinks should be taken to improve the state of health care in the home, based on the literature reviewed in this report examined through a human factors lens. They are organized into four areas: (1) health care technologies, including medical devices and health information technologies involved in health care in the home; (2)

caregivers and care recipients; (3) residential environments for health care; and (4) knowledge gaps that require additional research and development. Although many issues related to home health care could not be addressed, applications of human factors principles, knowledge, and research methods in these areas could make home health care safer and more effective and also contribute to reducing costs. The committee chose not to prioritize the recommendations, as they focus on various aspects of health care in the home and are of comparable importance to the different constituencies affected.

HEALTH CARE TECHNOLOGIES

Health care technologies include medical devices that are used in the home as well as information technologies related to home-based health care. The four recommendations in this area concern (1) regulating technologies for health care consumers, (2) developing guidance on the structure and usability of health information technologies, (3) developing guidance and standards for medical device labeling, and (4) improving adverse event reporting systems for medical devices. The adoption of these recommendations would improve the usability and effectiveness of technology systems and devices, support users in understanding and learning to use them, and improve feedback to government and industry that could be used to further improve technology for home care.

Ensuring the safety of emerging technologies is a challenge, in part because it is not always clear which federal agency has regulatory authority and what regulations must be met. Currently, the U.S. Food and Drug Administration (FDA) has responsibility for devices, and the Office of the National Coordinator for Health Information Technology (ONC) has similar authority with respect to health information technology. However, the dividing line between medical devices and health information technology is blurring, and many new systems and applications are being developed that are a combination of the two, although regulatory oversight has remained divided. Because regulatory responsibility for them is unclear, these products may fall into the gap.

The committee did not find a preponderance of evidence that knowledge is lacking for the design of safe and effective devices and technologies for use in the home. Rather than discovering an inadequate evidence base, we were troubled by the insufficient attention directed at the development of devices that account, necessarily and properly, for users who are inadequately trained or not trained at all. Yet these new users often must

rely on equipment without ready knowledge about limitations, maintenance requirements, and problems with adaptation to their particular home settings.

The increased prominence of the use of technology in the health care arena poses predictable challenges for many lay users, especially people with low health literacy, cognitive impairment, or limited technology experience. For example, remote health care management may be more effective when it is supported by technology, and various electronic health care (“e-health”) applications have been developed for this purpose. With the spectrum of caregivers ranging from individuals caring for themselves or other family members to highly experienced professional caregivers, computer-based care management systems could offer varying levels of guidance, reminding, and alerting, depending on the sophistication of the operator and the criticality of the message. However, if these technologies or applications are difficult to understand or use, they may be ignored or misused, with potentially deleterious effects on care recipient health and safety. Applying existing accessibility and usability guidelines and employing user-centered design and validation methods in the development of health technology products designed for use in the home would help ensure that they are safe and effective for their targeted user populations. In this effort, it is important to recognize how the line between medical devices and health information technologies has become blurred while regulatory oversight has remained distinct, and it is not always clear into which domain a product falls.

Recommendation 1. The U.S. Food and Drug Administration and the Office of the National Coordinator for Health Information Technology should collaborate to regulate, certify, and monitor health care applications and systems that integrate medical devices and health information technologies. As part of the certification process, the agencies should require evidence that manufacturers have followed existing accessibility and usability guidelines and have applied user-centered design and validation methods during development of the product.

Guidance and Standards

Developers of information technologies related to home-based health care, as yet, have inadequate or incomplete guidance regarding product content, structure, accessibility, and usability to inform innovation or evolution of personal health records or of care recipient access to information in electronic health records.

The ONC, in the initial announcement of its health information technology certification program, stated that requirements would be forthcom-

ing with respect both to personal health records and to care recipient access to information in electronic health records (e.g., patient portals). Despite the importance of these requirements, there is still no guidance on the content of information that should be provided to patients or minimum standards for accessibility, functionality, and usability of that information in electronic or nonelectronic formats.

Consequently, some portals have been constructed based on the continuity of care record. However, recent research has shown that records and portals based on this model are neither understandable nor interpretable by laypersons, even by those with a college education. The lack of guidance in this area makes it difficult for developers of personal health records and patient portals to design systems that fully address the needs of consumers.

Recommendation 2. The Office of the National Coordinator for Health Information Technology, in collaboration with the National Institute of Standards and Technology and the Agency for Healthcare Research and Quality, should establish design guidelines and standards, based on existing accessibility and usability guidelines, for content, accessibility, functionality, and usability of consumer health information technologies related to home-based health care.

The committee found a serious lack of adequate standards and guidance for the labeling of medical devices. Furthermore, we found that the approval processes of the FDA for changing these materials are burdensome and inflexible.

Just as many medical devices currently in use by laypersons in the home were originally designed and approved for use only by professionals in formal health care facilities, the instructions for use and training materials were not designed for lay users, either. The committee recognizes that lack of instructional materials for lay users adds to the level of risk involved when devices are used by populations for whom they were not intended.

Ironically, the FDA’s current premarket review and approval processes inadvertently discourage manufacturers from selectively revising or developing supplemental instructional and training materials, when they become aware that instructional and training materials need to be developed or revised for lay users of devices already approved and marketed. Changing the instructions for use (which were approved with the device) requires manufacturers to submit the device along with revised instructions to the FDA for another 510(k) premarket notification review. Since manufacturers can find these reviews complicated, time-consuming, and expensive, this requirement serves as a disincentive to appropriate revisions of instructional or training materials.

Furthermore, little guidance is currently available on design of user

training methods and materials for medical devices. Even the recently released human factors standard on medical device design (Association for the Advancement of Medical Instrumentation, 2009), while reasonably comprehensive, does not cover the topic of training or training materials. Both FDA guidance and existing standards that do specifically address the design of labeling and ensuing instructions for use fail to account for up-to-date findings from research on instructional systems design. In addition, despite recognition that requirements for user training, training materials, and instructions for use are different for lay and professional users of medical equipment, these differences are not reflected in current standards.

Recommendation 3. The U.S. Food and Drug Administration (FDA) should promote development (by standards development organizations, such as the International Electrotechnical Commission, the International Organization for Standardization, the American National Standards Institute, and the Association for the Advancement of Medical Instrumentation) of new standards based on the most recent human factors research for the labeling of and ensuing instructional materials for medical devices designed for home use by lay users. The FDA should also tailor and streamline its approval processes to facilitate and encourage regular improvements of these materials by manufacturers.

Adverse Event Reporting Systems

The committee notes that the FDA’s adverse event reporting systems, used to report problems with medical devices, are not user-friendly, especially for lay users, who generally are not aware of the systems, unaware that they can use them to report problems, and uneducated about how to do so. In order to promote safe use of medical devices in the home and rectify design problems that put care recipients at risk, it is necessary that the FDA conduct more effective postmarket surveillance of medical devices to complement its premarket approval process. The most important elements of their primarily passive surveillance system are the current adverse event reporting mechanisms, including Maude and MedSun. Entry of incident data by health care providers and consumers is not straightforward, and the system does not elicit data that could be useful to designers as they develop updated versions of products or new ones that are similar to existing devices. The reporting systems and their importance need to be widely promoted to a broad range of users, especially lay users.

Recommendation 4. The U.S. Food and Drug Administration should improve its adverse event reporting systems to be easier to use, to collect data that are more useful for identifying the root causes of events

related to interactions with the device operator, and to develop and promote a more convenient way for lay users as well as professionals to report problems with medical devices.

CAREGIVERS IN THE HOME

Health care is provided in the home by formal caregivers (health care professionals), informal caregivers (family and friends), and individuals who self-administer care; each type of caregiver faces unique issues. Properly preparing individuals to provide care at home depends on targeting efforts appropriately to the background, experience, and knowledge of the caregivers. To date, however, home health care services suffer from being organized primarily around regulations and payments designed for inpatient or outpatient acute care settings. Little attention has been given to how different the roles are for formal caregivers when delivering services in the home or to the specific types of training necessary for appropriate, high-quality practice in this environment.

Health care administration in the home commonly involves interaction among formal caregivers and informal caregivers who share daily responsibility for a person receiving care. But few formal caregivers are given adequate training on how to work with informal caregivers and involve them effectively in health decision making, use of medical or adaptive technologies, or best practices to be used for evaluating and supporting the needs of caregivers.

It is also important to recognize that the majority of long-term care provided to older adults and individuals with disabilities relies on family members, friends, or the individual alone. Many informal caregivers take on these responsibilities without necessary education or support. These individuals may be poorly prepared and emotionally overwhelmed and, as a result, experience stress and burden that can lead to their own morbidity. The committee is aware that informational and training materials and tested programs already exist to assist informal caregivers in understanding the many details of providing health care in the home and to ease their burden and enhance the quality of life of both caregiver and care recipient. However, tested materials and education, support, and skill enhancement programs have not been adequately disseminated or integrated into standard care practices.

Recommendation 5. Relevant professional practice and advocacy groups should develop appropriate certification, credentialing, and/or training standards that will prepare formal caregivers to provide care in the home, develop appropriate informational and training materials

for informal caregivers, and provide guidance for all caregivers to work effectively with other people involved.

RESIDENTIAL ENVIRONMENTS FOR HEALTH CARE

Health care is administered in a variety of nonclinical environments, but the most common one, particularly for individuals who need the greatest level and intensity of health care services, is the home. The two recommendations in this area encourage (1) modifications to existing housing and (2) accessible and universal design of new housing. The implementation of these recommendations would be a good start on an effort to improve the safety and ease of practicing health care in the home. It could improve the health and safety of many care recipients and their caregivers and could facilitate adherence to good health maintenance and treatment practices. Ideally, improvements to housing design would take place in the context of communities that provide transportation, social networking and exercise opportunities, and access to health care and other services.

Safety and Modification of Existing Housing

The committee found poor appreciation of the importance of modifying homes to remove health hazards and barriers to self-management and health care practice and, furthermore, that financial support from federal assistance agencies for home modifications is very limited. The general connection between housing characteristics and health is well established. For example, improving housing conditions to enhance basic sanitation has long been part of a public health response to acute illness. But the characteristics of the home can present significant barriers to autonomy or self-care management and present risk factors for poor health, injury, compromised well-being, and greater dependence on others. Conversely, physical characteristics of homes can enhance resident safety and ability to participate in daily self-care and to utilize effectively health care technologies that are designed to enhance health and well-being.

Home modifications based on professional home assessments can increase functioning, contribute to reducing accidents such as falls, assist caregivers, and enable chronically ill persons and people with disabilities to stay in the community. Such changes are also associated with facilitating hospital discharges, decreasing readmissions, reducing hazards in the home, and improving care coordination. Familiar modifications include installation of such items as grab bars, handrails, stair lifts, increased lighting, and health monitoring equipment as well as reduction of such hazards as broken fixtures and others caused by insufficient home maintenance.

Deciding on which home modifications have highest priority in a given

setting depends on an appropriate assessment of circumstances and the environment. A number of home assessment instruments and programs have been validated and proven to be effective to meet this need. But even if needed modifications are properly identified and prioritized, inadequate funding, gaps in services, and lack of coordination between the health and housing service sectors have resulted in a poorly integrated system that is difficult to access. Even when accessed, progress in making home modifications available has been hampered by this lack of coordination and inadequate reimbursement or financial mechanisms, especially for those who cannot afford them.

Recommendation 6. Federal agencies, including the U.S. Department of Health and Human Services and the Centers for Medicare & Medicaid Services, along with the U.S. Department of Housing and Urban Development and the U.S. Department of Energy, should collaborate to facilitate adequate and appropriate access to health- and safety-related home modifications, especially for those who cannot afford them. The goal should be to enable persons whose homes contain obstacles, hazards, or features that pose a home safety concern, limit self-care management, or hinder the delivery of needed services to obtain home assessments, home modifications, and training in their use.

Accessibility and Universal Design of New Housing

Almost all existing housing in the United States presents problems for conducting health-related activities because physical features limit independent functioning, impede caregiving, and contribute to such accidents as falls. In spite of the fact that a large and growing number of persons, including children, adults, veterans, and older adults, have disabilities and chronic conditions, new housing continues to be built that does not account for their needs (current or future). Although existing homes can be modified to some extent to address some of the limitations, a proactive, preventive, and effective approach would be to plan to address potential problems in the design phase of new and renovated housing, before construction.

Some housing is already required to be built with basic accessibility features that facilitate practice of health care in the home as a result of the Fair Housing Act Amendments of 1998. And 17 states and 30 cities have passed what are called “visitability” codes, which currently apply to 30,000 homes. Some localities offer tax credits, such as Pittsburgh through an ordinance, to encourage installing visitability features in new and renovated housing. The policy in Pittsburgh was impetus for the Pennsylvania Residential VisitAbility Design Tax Credit Act signed into law on October 28, 2006, which offers property owners a tax credit for new construction

and rehabilitation. The Act paves the way for municipalities to provide tax credits to citizens by requiring that such governing bodies administer the tax credit (Self-Determination Housing Project of Pennsylvania, Inc., n.d.).

Visitability, rather than full accessibility, is characterized by such limited features as an accessible entry into the home, appropriately wide doorways and one accessible bathroom. Both the International Code Council, which focuses on building codes, and the American National Standards Institute, which establishes technical standards, including ones associated with accessibility, have endorsed voluntary accessibility standards. These standards facilitate more jurisdictions to pass such visitability codes and encourage legislative consistency throughout the country. To date, however, the federal government has not taken leadership to promote compliance with such standards in housing construction, even for housing for which it provides financial support.

Universal design, a broader and more comprehensive approach than visitability, is intended to suit the needs of persons of all ages, sizes, and abilities, including individuals with a wide range of health conditions and activity limitations. Steps toward universal design in renovation could include such features as anti-scald faucet valve devices, nonslip flooring, lever handles on doors, and a bedroom on the main floor. Such features can help persons and their caregivers carry out everyday tasks and reduce the incidence of serious and costly accidents (e.g., falls, burns). In the long run, implementing universal design in more homes will result in housing that suits the long-term needs of more residents, provides more housing choices for persons with chronic conditions and disabilities, and causes less forced relocation of residents to more costly settings, such as nursing homes.

Issues related to housing accessibility have been acknowledged at the federal level. For example, visitability and universal design are in accord with the objectives of the Safety of Seniors Act (Public Law No. 110-202, passed in 2008). In addition, implementation of the Olmstead decision (in which the U.S. Supreme Court ruled that the Americans with Disabilities Act may require states to provide community-based services rather than institutional placements for individuals with disabilities) requires affordable and accessible housing in the community.

Visitability, accessibility, and universal design of housing all are important to support the practice of health care in the home, but they are not broadly implemented and incentives for doing so are few.

Recommendation 7. Federal agencies, such as the U.S. Department of Housing and Urban Development, the U.S. Department of Veterans Affairs, and the Federal Housing Administration, should take a lead role, along with states and local municipalities, to develop strategies that promote and facilitate increased housing visitability, accessibil-

ity, and universal design in all segments of the market. This might include tax and other financial incentives, local zoning ordinances, model building codes, new products and designs, and related policies that are developed as appropriate with standards-setting organizations (e.g., the International Code Council, the International Electrotechnical Commission, the International Organization for Standardization, and the American National Standards Institute).

RESEARCH AND DEVELOPMENT

In our review of the research literature, the committee learned that there is ample foundational knowledge to apply a human factors lens to home health care, particularly as improvements are considered to make health care safe and effective in the home. However, much of what is known is not being translated effectively into practice, neither in design of equipment and information technology or in the effective targeting and provision of services to all those in need. Consequently, the four recommendations that follow support research and development to address knowledge and communication gaps and facilitate provision of high-quality health care in the home. Specifically, the committee recommends (1) research to enhance coordination among all the people who play a role in health care practice in the home, (2) development of a database of medical devices in order to facilitate device prescription, (3) improved surveys of the people involved in health care in the home and their residential environments, and (4) development of tools for assessing the tasks associated with home-based health care.

Health Care Teamwork and Coordination

Frail elders, adults with disabilities, disabled veterans, and children with special health care needs all require coordination of the care services that they receive in the home. Home-based health care often involves a large number of elements, including multiple care providers, support services, agencies, and complex and dynamic benefit regulations, which are rarely coordinated. However, coordinating those elements has a positive effect on care recipient outcomes and costs of care. When successful, care coordination connects caregivers, improves communication among caregivers and care recipients and ensures that receivers of care obtain appropriate services and resources.

To ensure safe, effective, and efficient care, everyone involved must collaborate as a team with shared objectives. Well-trained primary health care teams that execute customized plans of care are a key element of coordinated care; teamwork and communication among all actors are also

essential to successful care coordination and the delivery of high-quality care. Key factors that influence the smooth functioning of a team include a shared understanding of goals, common information (such as a shared medication list), knowledge of available resources, and allocation and coordination of tasks conducted by each team member.

Barriers to coordination include insufficient resources available to (a) help people who need health care at home to identify and establish connections to appropriate sources of care, (b) facilitate communication and coordination among caregivers involved in home-based health care, and (c) facilitate communication among the people receiving and the people providing health care in the home.

The application of systems analysis techniques, such as task analysis, can help identify problems in care coordination systems and identify potential intervention strategies. Human factors research in the areas of communication, cognitive aiding and decision support, high-fidelity simulation training techniques, and the integration of telehealth technologies could also inform improvements in care coordination.

Recommendation 8 . The Agency for Healthcare Research and Quality should support human factors–based research on the identified barriers to coordination of health care services delivered in the home and support user-centered development and evaluation of programs that may overcome these barriers.

Medical Device Database

It is the responsibility of physicians to prescribe medical devices, but in many cases little information is readily available to guide them in determining the best match between the devices available and a particular care recipient. No resource exists for medical devices, in contrast to the analogous situation in the area of assistive and rehabilitation technologies, for which annotated databases (such as AbleData) are available to assist the provider in determining the most appropriate one of several candidate devices for a given care recipient. Although specialists are apt to receive information about devices specific to the area of their practice, this is much less likely in the case of family and general practitioners, who often are responsible for selecting, recommending, or prescribing the most appropriate device for use at home.

Recommendation 9. The U.S. Food and Drug Administration, in collaboration with device manufacturers, should establish a medical device database for physicians and other providers, including pharmacists, to use when selecting appropriate devices to prescribe or recommend

for people receiving or self-administering health care in the home. Using task analysis and other human factors approaches to populate the medical device database will ensure that it contains information on characteristics of the devices and implications for appropriate care recipient and device operator populations.

Characterizing Caregivers, Care Recipients, and Home Environments

As delivery of health care in the home becomes more common, more coherent strategies and effective policies are needed to support the workforce of individuals who provide this care. Developing these will require a comprehensive understanding of the number and attributes of individuals engaged in health care in the home as well as the context in which care is delivered. Data and data analysis are lacking to accomplish this objective.

National data regarding the numbers of individuals engaged in health care delivery in the home—that is, both formal and informal caregivers—are sparse, and the estimates that do exist vary widely. Although the Bureau of Labor Statistics publishes estimates of the number of workers employed in the home setting for some health care classifications, they do not include all relevant health care workers. For example, data on workers employed directly by care recipients and their families are notably absent. Likewise, national estimates of the number of informal caregivers are obtained from surveys that use different methodological approaches and return significantly different results.

Although numerous national surveys have been designed to answer a broad range of questions regarding health care delivery in the home, with rare exceptions such surveys reflect the relatively limited perspective of the sponsoring agency. For example,

• The Medicare Current Beneficiary Survey (administered by the Centers for Medicare & Medicaid Services) and the Health and Retirement Survey (administered by the National Institute on Aging) are primarily geared toward understanding the health, health services use, and/or economic well-being of older adults and provide no information regarding working-age adults or children or information about home or neighborhood environments.
• The Behavioral Risk Factors Surveillance Survey (administered by the Centers for Disease Control and Prevention, CDC), the National Health Interview Survey (administered by the CDC), and the National Children’s Study (administered by the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency) all collect information on health characteristics, with limited or no information about the housing context.
• The American Housing Survey (administered by the U.S. Department of Housing and Urban Development) collects detailed information regarding housing, but it does not include questions regarding the health status of residents and does not collect adequate information about home modifications and features on an ongoing basis.

Consequently, although multiple federal agencies collect data on the sociodemographic and health characteristics of populations and on the nation’s housing stock, none of these surveys collects data necessary to link the home, its residents, and the presence of any caregivers, thus limiting understanding of health care delivered in the home. Furthermore, information is altogether lacking about health and functioning of populations linked to the physical, social, and cultural environments in which they live. Finally, in regard to individuals providing care, information is lacking regarding their education, training, competencies, and credentialing, as well as appropriate knowledge about their working conditions in the home.

Better coordination across government agencies that sponsor such surveys and more attention to information about health care that occurs in the home could greatly improve the utility of survey findings for understanding the prevalence and nature of health care delivery in the home.

Recommendation 10. Federal health agencies should coordinate data collection efforts to capture comprehensive information on elements relevant to health care in the home, either in a single survey or through effective use of common elements across surveys. The surveys should collect data on the sociodemographic and health characteristics of individuals receiving care in the home, the sociodemographic attributes of formal and informal caregivers and the nature of the caregiving they provide, and the attributes of the residential settings in which the care recipients live.

Tools for Assessing Home Health Care Tasks and Operators

Persons caring for themselves or others at home as well as formal caregivers vary considerably in their skills, abilities, attitudes, experience, and other characteristics, such as age, culture/ethnicity, and health literacy. In turn, designers of health-related devices and technology systems used in the home are often naïve about the diversity of the user population. They need high-quality information and guidance to better understand user capabilities relative to the task demands of the health-related device or technology that they are developing.

In this environment, valid and reliable tools are needed to match users with tasks and technologies. At this time, health care providers lack the

tools needed to assess whether particular individuals would be able to perform specific health care tasks at home, and medical device and system designers lack information on the demands associated with health-related tasks performed at home and the human capabilities needed to perform them successfully.

Whether used to assess the characteristics of formal or informal caregivers or persons engaged in self-care, task analysis can be used to develop point-of-care tools for use by consumers and caregivers alike in locations where such tasks are encouraged or prescribed. The tools could facilitate identification of potential mismatches between the characteristics, abilities, experiences, and attitudes that an individual brings to a task and the demands associated with the task. Used in ambulatory care settings, at hospital discharge or other transitions of care, and in the home by caregivers or individuals and family members themselves, these tools could enable assessment of prospective task performer’s capabilities in relation to the demands of the task. The tools might range in complexity from brief screening checklists for clinicians to comprehensive assessment batteries that permit nuanced study and tracking of home-based health care tasks by administrators and researchers. The results are likely to help identify types of needed interventions and support aids that would enhance the abilities of individuals to perform health care tasks in home settings safely, effectively, and efficiently.

Recommendation 11. The Agency for Healthcare Research and Quality should collaborate, as necessary, with the National Institute for Disability and Rehabilitation Research, the National Institutes of Health, the U.S. Department of Veterans Affairs, the National Science Foundation, the U.S. Department of Defense, and the Centers for Medicare & Medicaid Services to support development of assessment tools customized for home-based health care, designed to analyze the demands of tasks associated with home-based health care, the operator capabilities required to carry them out, and the relevant capabilities of specific individuals.

Association for the Advancement of Medical Instrumentation. (2009). ANSI/AAMI HE75:2009: Human factors engineering: Design of medical devices. Available: http://www.aami.org/publications/standards/HE75_Ch16_Access_Board.pdf [April 2011].

Self-Determination Housing Project of Pennsylvania, Inc. (n.d.) Promoting visitability in Pennsylvania. Available: http://www.sdhp.org/promoting_visitability_in_pennsy.htm [March 30, 2011].

In the United States, health care devices, technologies, and practices are rapidly moving into the home. The factors driving this migration include the costs of health care, the growing numbers of older adults, the increasing prevalence of chronic conditions and diseases and improved survival rates for people with those conditions and diseases, and a wide range of technological innovations. The health care that results varies considerably in its safety, effectiveness, and efficiency, as well as in its quality and cost.

Health Care Comes Home reviews the state of current knowledge and practice about many aspects of health care in residential settings and explores the short- and long-term effects of emerging trends and technologies. By evaluating existing systems, the book identifies design problems and imbalances between technological system demands and the capabilities of users. Health Care Comes Home recommends critical steps to improve health care in the home. The book's recommendations cover the regulation of health care technologies, proper training and preparation for people who provide in-home care, and how existing housing can be modified and new accessible housing can be better designed for residential health care. The book also identifies knowledge gaps in the field and how these can be addressed through research and development initiatives.

Health Care Comes Home lays the foundation for the integration of human health factors with the design and implementation of home health care devices, technologies, and practices. The book describes ways in which the Agency for Healthcare Research and Quality (AHRQ), the U.S. Food and Drug Administration (FDA), and federal housing agencies can collaborate to improve the quality of health care at home. It is also a valuable resource for residential health care providers and caregivers.

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How To Write The Conclusion Chapter

A Simple Explainer With Examples + Free Template

By: Jenna Crossley (PhD) | Reviewed By: Dr. Eunice Rautenbach | September 2021

So, you’ve wrapped up your results and discussion chapters, and you’re finally on the home stretch – the conclusion chapter . In this post, we’ll discuss everything you need to know to craft a high-quality conclusion chapter for your dissertation or thesis project.

Overview: The Conclusion Chapter

• What the thesis/dissertation conclusion chapter is
• What to include in your conclusion
• How to structure and write up your conclusion
• A few tips  to help you ace the chapter
• FREE conclusion template

What is the conclusion chapter?

The conclusion chapter is typically the final major chapter of a dissertation or thesis. As such, it serves as a concluding summary of your research findings and wraps up the document. While some publications such as journal articles and research reports combine the discussion and conclusion sections, these are typically separate chapters in a dissertation or thesis. As always, be sure to check what your university’s structural preference is before you start writing up these chapters.

So, what’s the difference between the discussion and the conclusion chapter?

Well, the two chapters are quite similar , as they both discuss the key findings of the study. However, the conclusion chapter is typically more general and high-level in nature. In your discussion chapter, you’ll typically discuss the intricate details of your study, but in your conclusion chapter, you’ll take a   broader perspective, reporting on the main research outcomes and how these addressed your research aim (or aims) .

A core function of the conclusion chapter is to synthesise all major points covered in your study and to tell the reader what they should take away from your work. Basically, you need to tell them what you found , why it’s valuable , how it can be applied , and what further research can be done.

Whatever you do, don’t just copy and paste what you’ve written in your discussion chapter! The conclusion chapter should not be a simple rehash of the discussion chapter. While the two chapters are similar, they have distinctly different functions.  

What should I include in the conclusion chapter?

To understand what needs to go into your conclusion chapter, it’s useful to understand what the chapter needs to achieve. In general, a good dissertation conclusion chapter should achieve the following:

• Summarise the key findings of the study
• Explicitly answer the research question(s) and address the research aims
• Inform the reader of the study’s main contributions
• Discuss any limitations or weaknesses of the study
• Present recommendations for future research

Therefore, your conclusion chapter needs to cover these core components. Importantly, you need to be careful not to include any new findings or data points. Your conclusion chapter should be based purely on data and analysis findings that you’ve already presented in the earlier chapters. If there’s a new point you want to introduce, you’ll need to go back to your results and discussion chapters to weave the foundation in there.

In many cases, readers will jump from the introduction chapter directly to the conclusions chapter to get a quick overview of the study’s purpose and key findings. Therefore, when you write up your conclusion chapter, it’s useful to assume that the reader hasn’t consumed the inner chapters of your dissertation or thesis. In other words, craft your conclusion chapter such that there’s a strong connection and smooth flow between the introduction and conclusion chapters, even though they’re on opposite ends of your document.

Need a helping hand?

How to write the conclusion chapter

Now that you have a clearer view of what the conclusion chapter is about, let’s break down the structure of this chapter so that you can get writing. Keep in mind that this is merely a typical structure – it’s not set in stone or universal. Some universities will prefer that you cover some of these points in the discussion chapter , or that you cover the points at different levels in different chapters.

Step 1: Craft a brief introduction section

As with all chapters in your dissertation or thesis, the conclusions chapter needs to start with a brief introduction. In this introductory section, you’ll want to tell the reader what they can expect to find in the chapter, and in what order . Here’s an example of what this might look like:

This chapter will conclude the study by summarising the key research findings in relation to the research aims and questions and discussing the value and contribution thereof. It will also review the limitations of the study and propose opportunities for future research.

Importantly, the objective here is just to give the reader a taste of what’s to come (a roadmap of sorts), not a summary of the chapter. So, keep it short and sweet – a paragraph or two should be ample.

Step 2: Discuss the overall findings in relation to the research aims

The next step in writing your conclusions chapter is to discuss the overall findings of your study , as they relate to the research aims and research questions . You would have likely covered similar ground in the discussion chapter, so it’s important to zoom out a little bit here and focus on the broader findings – specifically, how these help address the research aims .

In practical terms, it’s useful to start this section by reminding your reader of your research aims and research questions, so that the findings are well contextualised. In this section, phrases such as, “This study aimed to…” and “the results indicate that…” will likely come in handy. For example, you could say something like the following:

This study aimed to investigate the feeding habits of the naked mole-rat. The results indicate that naked mole rats feed on underground roots and tubers. Further findings show that these creatures eat only a part of the plant, leaving essential parts to ensure long-term food stability.

Be careful not to make overly bold claims here. Avoid claims such as “this study proves that” or “the findings disprove existing the existing theory”. It’s seldom the case that a single study can prove or disprove something. Typically, this is achieved by a broader body of research, not a single study – especially not a dissertation or thesis which will inherently have significant  limitations . We’ll discuss those limitations a little later.

Step 3: Discuss how your study contributes to the field

Next, you’ll need to discuss how your research has contributed to the field – both in terms of theory and practice . This involves talking about what you achieved in your study, highlighting why this is important and valuable, and how it can be used or applied.

In this section you’ll want to:

• Mention any research outputs created as a result of your study (e.g., articles, publications, etc.)
• Inform the reader on just how your research solves your research problem , and why that matters
• Reflect on gaps in the existing research and discuss how your study contributes towards addressing these gaps
• Discuss your study in relation to relevant theories . For example, does it confirm these theories or constructively challenge them?
• Discuss how your research findings can be applied in the real world . For example, what specific actions can practitioners take, based on your findings?

Be careful to strike a careful balance between being firm but humble in your arguments here. It’s unlikely that your one study will fundamentally change paradigms or shake up the discipline, so making claims to this effect will be frowned upon . At the same time though, you need to present your arguments with confidence, firmly asserting the contribution your research has made, however small that contribution may be. Simply put, you need to keep it balanced .

Step 4: Reflect on the limitations of your study

Now that you’ve pumped your research up, the next step is to critically reflect on the limitations and potential shortcomings of your study. You may have already covered this in the discussion chapter, depending on your university’s structural preferences, so be careful not to repeat yourself unnecessarily.

There are many potential limitations that can apply to any given study. Some common ones include:

• Sampling issues that reduce the generalisability of the findings (e.g., non-probability sampling )
• Insufficient sample size (e.g., not getting enough survey responses ) or limited data access
• Low-resolution data collection or analysis techniques
• Researcher bias or lack of experience
• Lack of access to research equipment
• Time constraints that limit the methodology (e.g. cross-sectional vs longitudinal time horizon)
• Budget constraints that limit various aspects of the study

Discussing the limitations of your research may feel self-defeating (no one wants to highlight their weaknesses, right), but it’s a critical component of high-quality research. It’s important to appreciate that all studies have limitations (even well-funded studies by expert researchers) – therefore acknowledging these limitations adds credibility to your research by showing that you understand the limitations of your research design .

That being said, keep an eye on your wording and make sure that you don’t undermine your research . It’s important to strike a balance between recognising the limitations, but also highlighting the value of your research despite those limitations. Show the reader that you understand the limitations, that these were justified given your constraints, and that you know how they can be improved upon – this will get you marks.

Tips for a top-notch conclusion chapter

Now that we’ve covered the what , why and how of the conclusion chapter, here are some quick tips and suggestions to help you craft a rock-solid conclusion.

• Don’t ramble . The conclusion chapter usually consumes 5-7% of the total word count (although this will vary between universities), so you need to be concise. Edit this chapter thoroughly with a focus on brevity and clarity.
• Be very careful about the claims you make in terms of your study’s contribution. Nothing will make the marker’s eyes roll back faster than exaggerated or unfounded claims. Be humble but firm in your claim-making.
• Use clear and simple language that can be easily understood by an intelligent layman. Remember that not every reader will be an expert in your field, so it’s important to make your writing accessible. Bear in mind that no one knows your research better than you do, so it’s important to spell things out clearly for readers.

Hopefully, this post has given you some direction and confidence to take on the conclusion chapter of your dissertation or thesis with confidence. If you’re still feeling a little shaky and need a helping hand, consider booking a free initial consultation with a friendly Grad Coach to discuss how we can help you with hands-on, private coaching.

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O’Hara R, Johnson M, Hirst E, et al. A qualitative study of decision-making and safety in ambulance service transitions. Southampton (UK): NIHR Journals Library; 2014 Dec. (Health Services and Delivery Research, No. 2.56.)

A qualitative study of decision-making and safety in ambulance service transitions.

Chapter 8 conclusions and recommendations.

The aim of this study was to explore the range and nature of influences on safety in decision-making by ambulance service staff (paramedics). A qualitative approach was adopted using a range of complementary methods. The study has provided insights on the types of decisions that staff engage in on a day-to-day basis. It has also identified a range of system risk factors influencing decisions about patient care. Although this was a relatively small-scale exploratory study, confidence in the generalisability of the headline findings is enhanced by the high level of consistency in the findings, obtained using multiple methods, and the notable consensus among participants.

The seven predominant system influences identified should not be considered discrete but as overlapping and complementary issues. They also embody a range of subthemes that represent topics for future research and/or intervention.

The apparently high level of consistency across the participating trusts suggests that the issues identified may be generic and relevant to other ambulance service trusts.

In view of the remit of this study, aspects relating to system weaknesses and potential threats to patient safety dominate in the account of findings. However, it should be noted that respondent accounts also provided examples of systems that were said to be working well, for example specific care management pathways, local roles and ways of working and technological initiatives such as IBIS and the ePRF.

• Implications for health care

The NHS system within which the ambulance service operates is characterised in our study as fragmented and inconsistent. For ambulance service staff the extent of variation across the geographical areas in which they work is problematic in terms of knowing what services are available and being able to access them. The lack of standardisation in practice guidelines, pathways and protocols across services and between areas makes it particularly challenging for staff to keep up to date with requirements in different parts of their own trust locations and when crossing trust boundaries. Although a degree of consistency across the network is likely to improve the situation, it is also desirable to have sufficient flexibility to accommodate the needs of specific local populations. There was some concern over the potential for further fragmentation with the increased number of CCGs.

Ambulance services are increasingly under pressure to focus on reducing conveyance rates to A&E; this arguably intensifies the need to ensure that crews are appropriately skilled to be able to make effective decisions over the need to convey or not to convey if associated risks to patients are to be minimised. Our findings highlight the challenges of developing staff and ensuring that their skills are utilised where they are most needed within the context of organisational resource constraints and operational demands. Decisions over non-conveyance to A&E are moderated by the availability of alternative care pathways and providers. There were widespread claims of local variability in this respect. Staff training and development, and access to alternatives to A&E, were identified as priorities for attention by workshop attendees.

One of the difficulties for ambulance services is that they operate as a 24/7 service within a wider urgent and emergency care network that, beyond A&E, operates a more restricted working day. The study findings identify this as problematic for two reasons. First, it fuels demand for ambulance service care as a route to timely treatment, when alternatives may involve delay. Second, it contributes to inappropriate conveyance to A&E because more appropriate options are unavailable or limited during out-of-hours periods. Ultimately, this restricts the scope for ensuring that patients are getting the right level of care at the right time and place. Study participants identified some patient populations as particularly poorly served in terms of alternatives to A&E (e.g. those with mental health issues, those at the end of life, older patients and those with chronic conditions).

The effectiveness of the paramedic role in facilitating access to appropriate care pathways hinges on relationships with other care providers (e.g. primary care, acute care, mental health care, community health care). An important element relates to the cultural profile of paramedics in the NHS, specifically, the extent to which other health professionals and care providers consider the clinical judgements/decisions made by paramedics as credible and actionable. Staff identified this as a barrier to access where the ambulance service is still viewed primarily as a transport service. Consideration could be given to ways of improving effective teamworking and communication across service and professional boundaries.

Although paramedics acknowledged the difficulties of telephone triage, they also identified how the limitations of this system impact on them. Over-triage at the initial call-handling stage places considerable demands on both staff and vehicle resources. A related concern is the limited information conveyed to crews following triage. Initial triage was suggested as an area that warrants attention to improve resource allocation.

The findings highlight the challenges faced by front-line ambulance service staff. It was apparent that the extent and nature of the demand for ambulance conveyance represents a notable source of strain and tension for individuals and at an organisational level. For example, there were widespread claims that meeting operational demands for ambulance services limits the time available for training and professional development, with this potentially representing a risk for patients and for staff. Staff perceptions of risk relating to patient safety extend to issues of secondary risk management, that is, personal and institutional liabilities, in particular risks associated with loss of professional registration. The belief that they are more likely to be blamed than supported by their organisation in the event of an incident was cited by staff as a source of additional anxiety when making more complex decisions. This perceived vulnerability can provoke excessively risk-averse decisions. These issues merit further attention to examine the workforce implication of service delivery changes, including how to ensure that staff are appropriately equipped and supported to deal effectively with the demands of their role.

Paramedics identified a degree of progress in relation to the profile of patient safety within their organisations but the apparent desire within trusts to prioritise safety improvement was felt to be constrained by service demands and available resources. Attempts to prioritise patient safety appear to focus on ensuring that formal systems are in place (e.g. reporting and communication). Concerns were expressed over how well these systems function to support improvement, for example how incident reports are responded to and whether lessons learned are communicated to ambulance staff within and between trusts. Consideration could be given to identifying ways of supporting ambulance service trusts to develop the safety culture within their organisation.

Service users attributed the increased demand for ambulance services to difficulties in identifying and accessing alternatives. They were receptive to non-conveyance options but felt that lack of awareness of staff roles and skills may cause concern when patients expect conveyance to A&E.

• Recommendations for research

The workshop attendees identified a range of areas for attention in relation to intervention and research, which are provided in Chapter 6 (see Suggestions for potential interventions and research ). The following recommendations for research are based on the study findings:

• Limited and variable access to services in the wider health and social care system is a significant barrier to reducing inappropriate conveyance to A&E. More research is needed to identify effective ways of improving the delivery of care across service boundaries, particularly for patients with limited options at present (e.g. those with mental health issues, those at the end of life and older patients). Research should address structural and attitudinal barriers and how these might be overcome.
• Ambulance services are increasingly focused on reducing conveyance to A&E and they need to ensure that there is an appropriately skilled workforce to minimise the potential risk. The evidence points to at least two issues: (1) training and skills and (2) the cultural profile of paramedics in the NHS, that is, whether others view their decisions as credible. Research could explore the impact of enhanced skills on patient care and on staff, for example the impact of increased training in urgent rather than emergency care. This would also need to address potential cultural barriers to the effective use of new skills.
• Research to explore the impact of different aspects of safety culture on ambulance service staff and the delivery of patient care (e.g. incident reporting, communication, teamworking, and training) could include comparisons across different staff groups and the identification of areas for improvement, as well as interventions that could potentially be tested.
• The increased breadth of decision-making by ambulance service crews with advanced skills includes more diagnostics; therefore, there is a need to look at the diagnostic process and potential causes of error in this environment.
• There is a need to explore whether there are efficient and safe ways of improving telephone triage decisions to reduce over-triage, particularly in relation to calls requiring an 8-minute response. This could include examining training and staffing levels, a higher level of clinician involvement or other forms of decision support.
• There is a need to explore public awareness of, attitudes towards, beliefs about and expectations of the ambulance service and the wider urgent and emergency care network and the scope for behaviour change interventions, for example communication of information about access to and use of services; empowering the public through equipping them with the skills to directly access the services that best meet their needs; and informing the public about the self-management of chronic conditions.
• A number of performance measures were identified engendering perverse motivations leading to suboptimal resource utilisation. An ongoing NIHR Programme Grant for Applied Research (RP-PG-0609–10195; ‘Pre-hospital Outcomes for Evidence-Based Evaluation’) aims to develop new ways of measuring ambulance service performance. It is important that evaluations of new performance metrics or other innovations (e.g. Make Ready ambulances, potential telehealth technologies or decision-support tools) address their potential impact on patient safety.

Included under terms of UK Non-commercial Government License .

• Cite this Page O’Hara R, Johnson M, Hirst E, et al. A qualitative study of decision-making and safety in ambulance service transitions. Southampton (UK): NIHR Journals Library; 2014 Dec. (Health Services and Delivery Research, No. 2.56.) Chapter 8, Conclusions and recommendations.
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• Epigenome-wide association study of lung cancer among never smokers in two prospective cohorts in Shanghai, China
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• http://orcid.org/0000-0001-8322-0495 Mohammad L Rahman 1 ,
• Charles E Breeze 1 ,
• Xiao-Ou Shu 2 ,
• http://orcid.org/0009-0007-3690-1168 Jason Y Y Wong 1 ,
• http://orcid.org/0000-0001-7610-2554 Batel Blechter 1 ,
• Andres Cardenas 3 ,
• Xuting Wang 4 ,
• Bu-Tian Ji 1 ,
• Qiuyin Cai 5 ,
• H Dean Hosgood 6 ,
• Gong Yang 7 ,
• Jianxin Shi 1 ,
• Jirong Long 7 ,
• Yu-Tang Gao 8 ,
• Douglas A Bell 4 ,
• Wei Zheng 2 ,
• Nathaniel Rothman 1 ,
• 1 Division of Cancer Epidemiology and Genetics , National Cancer Institute , Rockville , Maryland , USA
• 2 Vanderbilt University Medical Center , Nashville , Tennessee , USA
• 3 Department of Epidemiology and Population Health , Stanford University , Stanford , California , USA
• 4 Immunity, Inflammation and Diseases Laboratory , National Institute of Environmental Health Sciences , Research Triangle Park , North Carolina , USA
• 5 Vanderbilt University , Nashville , Tennessee , USA
• 6 Albert Einstein College of Medicine , Bronx , New York , USA
• 7 Department of Medicine , Vanderbilt-Ingram Cancer Center , Nashville , Tennessee , USA
• 8 Shanghai Cancer Institute , Shanghai , China
• Correspondence to Dr Mohammad L Rahman, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD 20850, USA; mohammad.rahman2{at}nih.gov

Background The aetiology of lung cancer among individuals who never smoked remains elusive, despite 15% of lung cancer cases in men and 53% in women worldwide being unrelated to smoking. Epigenetic alterations, particularly DNA methylation (DNAm) changes, have emerged as potential drivers. Yet, few prospective epigenome-wide association studies (EWAS), primarily focusing on peripheral blood DNAm with limited representation of never smokers, have been conducted.

Methods We conducted a nested case-control study of 80 never-smoking incident lung cancer cases and 83 never-smoking controls within the Shanghai Women’s Health Study and Shanghai Men’s Health Study. DNAm was measured in prediagnostic oral rinse samples using Illumina MethylationEPIC array. Initially, we conducted an EWAS to identify differentially methylated positions (DMPs) associated with lung cancer in the discovery sample of 101 subjects. The top 50 DMPs were further evaluated in a replication sample of 62 subjects, and results were pooled using fixed-effect meta-analysis.

Results Our study identified three DMPs significantly associated with lung cancer at the epigenome-wide significance level of p<8.22×10 −8 . These DMPs were identified as cg09198866 ( MYH9 ; TXN2 ), cg01411366 ( SLC9A10 ) and cg12787323. Furthermore, examination of the top 1000 DMPs indicated significant enrichment in epithelial regulatory regions and their involvement in small GTPase-mediated signal transduction pathways. Additionally, GrimAge acceleration was identified as a risk factor for lung cancer (OR=1.19 per year; 95% CI 1.06 to 1.34).

Conclusions While replication in a larger sample size is necessary, our findings suggest that DNAm patterns in prediagnostic oral rinse samples could provide novel insights into the underlying mechanisms of lung cancer in never smokers.

• lung cancer
• non-small cell lung cancer
• tobacco and the lung

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information. All data generated or analysed during this study are included in this published article and its supplementary information files. For original data, please contact the corresponding author, MLR, at [email protected].

https://doi.org/10.1136/thorax-2023-220352

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WHAT IS ALREADY KNOWN ON THIS TOPIC

Few prospective studies on epigenome-wide DNA methylation (DNAm), DNAm-based ageing and lung cancer have ever been conducted; all were focused on DNAm patterns in peripheral blood and had limited inclusion of never smokers. These studies identified specific CpG sites associated with lung cancer, influenced by smoking, with the AHRR gene standing out. Despite some shared CpG findings between ever and never smokers, none of these CpG sites demonstrated a broad epigenome-wide significance in the relatively small subset of never smokers studied.

WHAT THIS STUDY ADDS

To our knowledge, this study marks the first prospective epigenome-wide association study of lung cancer among never smokers using oral rinse samples. Multiple differentially methylated positions (DMPs) associated with lung cancer in never smokers were identified. Top DMPs exhibited significant enrichment in epithelial regulatory regions and linked to small GTPase-mediated signal transduction pathways, implicated in lung carcinogenesis. Additionally, GrimAge acceleration was associated with an increased lung cancer risk among never smokers.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

Subject to validation in a larger sample size, our findings suggest that changes in DNAm patterns in prediagnostic oral rinse samples may provide novel insights into the pathogenesis of lung cancer and its risk factors, particularly in individuals who have never smoked. These non-invasive samples, which consist of a mixture of epithelial and other upper airway cell types directly exposed to various air pollutants, offer a valuable medium to identify aetiological markers of diseases originating from epithelial tissues, such as lung cancer.

Introduction

Lung cancer is the second most common cancer and the leading cause of cancer deaths globally, accounting for an estimated 2.21 million new cases and 1.80 million deaths in 2020. 1 Although smoking is a well-established risk factor, a substantial proportion of cases (15% in men and 53% in women worldwide) occur in non-smokers. 2 Notably, the rate of lung cancer among never smokers is the highest among Asian women, 3 a trend mirrored in ethnically Chinese women in the USA. 4 For instance, 57% of never-smoking women with lung cancer in the USA are of Asian or Pacific Islander descent. 5 The aetiology of lung cancer in never smokers is complex, involving environmental, occupational, lifestyle and genetic factors. Despite ongoing research, a complete understanding of the precise mechanisms behind lung cancer in never smokers remains elusive.

Factors unrelated to smoking, notably exposures to fine particulate matter (PM 2.5 ) 6 7 and secondhand tobacco smoke, share common carcinogenic constituents with tobacco smoke 7 and are associated with lung cancer among never smokers. 8 Epigenetic modifications, particularly changes in DNA methylation (DNAm), have emerged as potential markers to understand the cumulative effect of non-smoking environmental exposures in lung cancer development in never smokers. For example, AHRR gene hypomethylation, typically associated with smoking, is observed in never smokers exposed to PM 2.5 and secondhand smoke. 9 10 Additionally, exposure to benzo(a)pyrene, a potent carcinogenic polycyclic aromatic hydrocarbon (PAH) derived from smoking and household coal and biomass combustion, is associated with altered blood DNAm patterns and lung cancer. 11

A few prospective studies have linked DNAm in prediagnostic samples, identifying CpG sites, most notably within the AHRR gene, that were associated with lung cancer. 12 13 However, these studies included a limited number of never smokers, and none of the CpG sites achieved epigenome-wide significance within this subgroup. 12 14 15 Additionally, these studies exclusively relied on DNAm measurements in peripheral blood leucocytes, which are histologically different from the cells that give rise to lung cancer. Given that most lung cancers develop from epithelial cells lining the airways, DNAm in peripheral blood connective tissue cells may not adequately capture the underlying molecular changes directly related to lung cancer development.

The current study examines DNAm in oral rinse samples, encompassing a mixture of epithelial and other upper airway cell types directly exposed to air pollution. This non-invasive and easily collectable sample provides a valuable medium for identifying potential aetiological markers of diseases originating from epithelial tissues, such as lung cancer. We conducted this investigation within a never-smoking population from two prospective cohorts in Shanghai, making it the largest prospective study on DNAm and lung cancer to date among never smokers. This approach minimises the possibility of residual confounding from smoking and aids in identifying DNAm signatures that might be unique to this population. The aim of this study was to identify DNAm biomarkers associated with lung cancer using prediagnostic oral rinse samples from individuals who never smoked.

Study participants and design

The study, depicted in figure 1 and online supplemental file 2 , is a nested case–control study within the Shanghai Women’s Health Study (SWHS) and the Shanghai Men’s Health Study (SMHS), with respective recruitments between 1996–2000 (n=74 941) and 2002–2006 (n=61 480). 16 17 These population-based prospective cohort studies in Shanghai, China involved multiple in-person interviews to obtain information on demographics, occupational and environmental exposures, lifestyle, dietary and other factors. The participation rates in both cohorts were high (SWHS=92.7%; SMHS=74.0%). 16 17 Cohort members were followed for cancer diagnoses through in-person surveys administered every 2–3 years and annual record linkage with the Shanghai Cancer Registry and Vital Statistics Unit.

Supplemental material

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Overview of oral cell DNA methylation (DNAm) and future risk of lung cancer in never smokers from SMHS and SWHS: study design, study information, sample size and number of significant differentially methylated positions (DMPs) for discovery, replication and pooled analyses.

Eligible cases included incident lung cancer in individuals who never smoked (<100 cigarettes in lifetime) with available oral rinse samples. Using the incidence-density method, we randomly selected one never-smoking control for each index case matched on age at baseline (within±2 years), sex, sampling time (morning/afternoon), recent use of antibiotics and menopausal status. The diagnosis of lung cancer was determined using the International Classification of Diseases-Ninth Revision code 162. Lung cancer diagnoses spanned 2000–2014 in SWHS (average follow-up: 7.0 years, range: 0–13 years) and 2003–2013 in SMHS (average follow-up: 5.2 years, range: 1–10 years).

DNA extraction and DNAm measurements

Oral rinse samples were collected during study enrolment using a mouth rinse technique. DNA was isolated using the DNeasy PowerSoil Kit (Qiagen). Bisulfite-converted DNA was employed to assess genome-wide DNAm using Infinium MethylationEPIC BeadChip Array (Illumina, California, USA). Samples were grouped into three projects based on the shipment date, with the largest project (project 2) including 111 (63.4%) samples.

Calculation of epigenetic ageing biomarkers

Epigenetic age was calculated using the online Horvath calculator ( http://dnamage.genetics.ucla.edu/ ) with advance analysis option. 18 Epigenetic age acceleration (EAA) measures were obtained, indicating biological ageing relative to chronological age. Extrinsic EAA and intrinsic EAA for Horvath’s clock were also assessed, considering the age-related changes in blood cell counts due to immune system ageing.

Statistical analysis

We processed raw DNAm image files using R statistical software ( www.r-project.org/ ) and several Bioconductor packages, including the ChAMP pipeline, 19 with default parameters. Samples exhibiting poor performance (>10% failed probes) were excluded, removing 12 samples. Further exclusions comprised 177 239 probes with detection p value <0.01, 332 probes with bead count <3 in at least 5% of samples, 1511 no-CpG probes, 78 915 single-nucleotide polymorphism probes and 11 multihit probes. A total of 607 910 probes meeting quality control criteria were used in subsequent statistical analyses. Missing values were imputed using the K-nearest neighbour method, and data were normalised using Beta Mixture Quantile normalisation. 20 Correction for potential batch effects related to sample plate, array and slide was done using ComBat. 21 We visualised density distributions for samples at all processing steps ( online supplemental figure 1 ). DNAm at each CpG site is reported as beta values, indicating the fraction of methylated DNA molecules at the target CpG (ranging from 0 to 1). Epigenetic Dissection of Intra-Sample Heterogeneity, a reference-based method, estimated cell-type proportions. 22

Differentially methylated positions and lung cancer risk

In a two-stage analysis, comprising a discovery phase (n=101) and a replication phase (n=62), we aimed to identify differentially methylated positions (DMPs) associated with lung cancer. Robust linear regression models were employed on an M-value scale with adjustments for age, sex, sample plate and estimated cell-type proportions. Nonetheless, we reported coefficients and SEs on the beta value scale for easy interpretation. Unmatched analysis was performed to preserve the maximum sample size. Epigenome-wide association study (EWAS) model fit was evaluated using quantile-quantile plots and the genomic inflation factor (λ). Manhattan and volcano plots illustrated EWAS findings, with an epigenome-wide significance threshold set at p<8.22×10 −08 , applying a Bonferroni correction. The top 50 DMPs identified based on p values from the discovery phase were tested for replication in the second set using similar models. Findings from both phases were combined using a fixed-effect meta-analysis. DMPs achieving a p value threshold of <8.22×10 –08 were selected for subsequent analysis.

Unconditional logistic regression models were then applied to these DMPs using DNAm M-values as both continuous and categorical variables (divided into tertiles based on distributions in controls). The Firth bias correction method addressed potential separation issues in categorical model using the ‘logistf’ function in R. 23 The assessment of trends across tertiles of methylation M-values was conducted using a linear trend test or Cochran-Armitage trend test, as appropriate. In the sensitivity analysis, we conducted an EWAS in the combined sample (n=163). Additionally, we conducted a stratified analysis by sex for selected DMPs surpassing the epigenome-wide significance threshold, along with testing for an interaction between sex and the respective DMP in the combined sample.

In silico annotation of DMPs using eFORGE, and pathway analyses

We performed a functional overlap analysis using eFORGE ( https://eforge.altiusinstitute.org/ ) with default settings, examining the top 1000 DMPs from the discovery and pooled EWAS for enrichment across (1) hidden Markov model (HMM) chromatin states and (2) histone mark broadPeaks from the Roadmap Epigenomics Consortium. 24 Additionally, we conducted pathway enrichment analysis using gene information from the top 1000 DMPs in GOrilla ( http://cbl-gorilla.cs.technion.ac.il/ ), applying false discovery rate (FDR) to identify significantly enriched pathways.

Epigenetic ageing and lung cancer risk

Estimated epigenetic age was evaluated through scatterplots and examining empirical correlations with chronological age. Unconditional logistic regression models, with adjustments for age and sex, were employed to evaluate the association between DNAm ageing and lung cancer.

Out of the 163 participants (80 lung cancer cases and 83 controls) used in the final analysis, 38 individuals were enlisted in the SMHS (19 cases and 19 controls), while 125 individuals were enlisted in the SWHS (64 cases and 61 controls) ( table 1 ). The discovery analysis included 101 participants, representing 62% of the total sample, which included 57 lung cancer cases and 44 controls. Among the lung cancer cases with available tumour histology data, 31 (38.8%) were classified as adenocarcinoma, and 41 (51.3%) remained unclassified.

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Distribution of selected characteristics by lung cancer status

DMPs and lung cancer risk

Findings from the discovery analysis, follow-up replication and subsequent pooled analysis using meta-analysis are illustrated in figure 2 and summarised in table 2 (with complete findings detailed in online supplemental table 1 ). In the discovery analysis, a single DMP was identified, showing a significant association with lung cancer at the epigenome-wide level of p<8.22E-08 (cg01411366: coefficient=−0.095, p=7.23E-08; SLC9A10 ). This association was confirmed in the replication analysis (β=−0.079, p=0.047). In the meta-analysis, two additional DMPs were identified: cg09198866 (p=5.39E-09, MYH9 ; TXN2 ) and cg12787323 (p=2.72E-08), while cg01411366 (p=1.02E-08) remained statistically significant with lung cancer at p<8.22E-08. Specifically, the meta-analysis reveals that hypomethylation of cg09198866 and cg01411366, alongside hypermethylation of cg12787323, corresponding to alterations of 1.7%, 9.3% and 3.1% on the beta value scale, respectively, were associated with a higher risk of developing lung cancer. It is noteworthy that the magnitude and direction of these associations remained fairly consistent across the different stages of analysis. The findings broadly aligned with the combined epigenome-wide analysis, pooling together discovery and replication samples, with the exception that cg00811020 ( NAA30 ) and cg05658193 ( EIF2A ; SERPA ) demonstrated significant association with lung cancer at p<8.22E-08 ( online supplemental table 2 ).

Overview of results from oral cell DNA methylation (DNAm) and lung cancer development in prospective Shanghai cohorts. A1, A2 and A3 illustrate the Manhattan, volcano and quantile-quantile plots from epigenome-wide DNA methylation analysis in the discovery phase. The Manhattan plot (A1) presents a graphical representation of the association between DNAm sites (CpGs) across the genome and their corresponding p values. Each dot represents a CpG site; its position along the x-axis indicating genomic location, and the y-axis shows the negative logarithm of the p value. Significant associations are indicated by dots that rise above the dotted horizontal line, representing the epigenome-wide significance level of p<8.22E-08. The volcano plot (A2) displays statistical significance (p values) against the effect size (changes in DNAm M-value) for each CpG site. The quantile-quantile plot (A3) compares the distribution of observed p values to the expected distribution under the null hypothesis, along with the genomic inflation parameter, lambda (λ) value. B1, B2 and B3 illustrate box plots, comparing raw methylation beta values between lung cancer cases and controls in Discovery (B1), Replication (B2) and Pooled (B3) samples, for top-hit differentially methylated positions (DMPs) selected from meta-analysis. C1, C2 and C3 illustrate ORs and 95% CIs for lung cancer across tertiles of DNAm M-values in Discovery (C1), Replication (C2) and Pooled (C3) analyses.

Top DMPs with lung cancer risk in the discovery, replication and pooled analyses, sorted by the smallest p value in the pooled analysis

The logistic regression models supported these findings, demonstrating significant associations between these three DMPs and lung cancer across discovery, replication and meta-analyses ( figure 2 , online supplemental table 3 ). Moreover, the categorical analysis revealed a significant and largely consistent monotonic trend across tertiles of these DMPs. In analysis stratified by sex, the effect of these three DMPs on lung cancer appeared to be more pronounced in males, although none of the DMPs exhibited a significant interaction with sex in the pooled sample ( online supplemental table 4 ).

Overlap of lung cancer-associated DMPs with genes and regulatory elements

To understand the regulatory context of DMPs, we mapped them to the nearest gene, epigenomic peaks, tissue-specific gene expression via RNA-seq and chromatin interaction annotations ( figure 3 ). Notably, cg01411366 is located within a regulatory element linked to the SLC9A10 gene. Conversely, cg09198866 resides in an intergenic region distal to TXN2 and MYH9 genes. Transcription factor binding site analysis and other annotations suggest a regulatory element overlap, yet the specific target gene remains unclear. For cg12787323, located intergenically around 200 kb from the nearest gene, it did not coincide with known enhancer elements or enhancer–promoter interactions according to GeneHancer, presenting interpretational challenges.

Lung cancer-associated differentially methylated positions (DMPs). DMP browser shot displays (in order from the top): genomic coordinates, gene locations, H3K27ac peaks for seven ENCODE cell lines and ENCODE chromatin state segmentations, and chromatin accessibility data of (A) cg09198866 ( MYH9 ; TXN2 ); (B) cg01411366 ( SLC9A10 ); and (C) cg12787323. These data indicate that cg09198866 is located in an intergenic region distal to the TXN2 and MYH9 genes. Transcription factor binding site (TFBS) analysis and other annotations suggested a regulatory element overlap, but the specific target gene is unclear. Conversely, cg01411366 is located on the regulatory element of the SLC9A10 gene. For cg12787323, located intergenically around 200 kb from the nearest gene, it does not overlap with known enhancer elements or enhancer–promoter interactions according to GeneHancer, presenting interpretational challenges. This browser shot was generated using the UCSC Genome Browser ( https://genome.ucsc.edu/ ) on human genome build hg19.

Integrative epigenomic analysis of DMPs using eFORGE, and pathway analyses

Integrative epigenomic analysis using eFORGE 24 showed enrichment for HMM chromatin states and histone mark broadPeaks related to epithelial, muscle and lung tissues ( figure 4 , complete findings are presented in online supplemental figure 2 ). Consistent results were observed for top CpGs from the discovery EWAS across diverse study subsets ( online supplemental figure 3 ). Pathway analysis indicated enrichment for several pathways ( online supplemental figure 4 ), with the ‘regulation of small GTPase mediated signal transduction’ being the sole significant pathway after multiple testing correction using FDR<0.05. Taken together, gene ontology and FORGE2 results suggest a potential involvement of small GTPases and epithelial regulatory elements in the identified top DMPs in our study.

Tissue-specific integrative analysis indicates a potential effect on lung regulatory elements. (A) eFORGE analysis for top 1000 lung cancer-related differentially methylated positions (DMPs) in the pooled epigenome-wide association studies (EWAS) in never smokers: the x-axis indicates tissues/cell-type samples used in the analysis; the y-axis shows eFORGE enrichment (−log10 p value) with Roadmap Epigenomics histone mark broadPeaks. The highest ranked sample set (indicated by the highest points) shows significant enrichment for lung, muscle, thymus and skin, including for H3K4me1, an enhancer-associated histone mark. (B) eFORGE analysis for the top 1000 lung cancer-related DMPs in the pooled EWAS: the x-axis indicates tissues/cell-type samples used in the analysis; the y-axis shows eFORGE enrichment (−log10 p value) with Roadmap Epigenomics chromatin states for a range of tissue samples. The highest ranked sample set (indicated by the highest points) shows the most significant enrichment in epithelial cells with notable enrichment also seen in muscle and lung tissues, including for the ‘Enhancer’ chromatin state category. FDR, false discovery rate.

EAA and the risk of lung cancer

Our analysis demonstrated robust correlations (Pearson’s correlation coefficient, r=0.61–0.87) between chronological age and epigenetic clocks, which are DNAm-based markers originally developed from various tissues and organ types ( online supplemental figure 5 ). This indicates that the epigenetic age markers calculated based on oral cell DNAm in our study performed well, despite potential differences in tissue specificity among the clocks. In logistic regression models, EAA, as measured by GrimAge clock, was associated with a higher risk of lung cancer (OR=1.19 per year of acceleration; 95% CI 1.06, 1.34) ( figure 5 ). These associations remained consistent in sensitivity analyses, even with further adjustments for secondhand smoke exposure (data not included). No associations with lung cancer were observed for other epigenetic clocks assessed in this study.

Associations between epigenetic age acceleration (EAA) and incident lung cancer in never smokers. Diamonds represent ORs, error bars indicate 95% CIs per year of EAA and the red dotted line signifies the null hypothesis. EEAA, extrinsic EAA IEAA, intrinsic EAA.

In this study, involving lung cancer cases and controls nested within two large prospective cohorts in Shanghai, China, we assessed DNAm in oral rinse samples and identified three DMPs associated with the development of lung cancer using an agnostic epigenome-wide approach. Specifically, hypomethylation of cg09198866 ( MYH9 ; TXN2 ) and cg01411366 ( SLC9A10 ), as well as hypermethylation of cg12787323, was associated with an increased risk of lung cancer. Lung cancer-related DMPs exhibited significant enrichment in regions that regulate epithelial functions and were linked to the regulation of small GTPase-mediated signal transduction pathways, which are implicated in lung carcinogenesis. While our findings require confirmation through studies with larger sample sizes, they suggest that DNAm patterns in prediagnostic oral rinse samples could potentially serve as novel aetiological markers of lung cancer.

The precise biological mechanisms underlying the associations between the notably identified DMPs and lung cancer are not fully understood. The DMP cg09198866 is located in an intergenic region, distant from two genes —TXN2 and MYH9 . This DMP overlaps with a regulatory element; however, the specific gene it affects remains undetermined. TXN2 encodes a mitochondrial thioredoxin family member, essential for modulating mitochondrial membrane potential and defending against oxidative stress. It significantly impacts ferroptosis, a novel iron-dependent lipid peroxidation-induced cell death, distinct from apoptosis. Cancer cells require robust antioxidative and anti-ferroptosis mechanisms for survival in oxidising conditions. The upregulation of the Na + -independent cystine/glutamate antiporter (system Xc − ), comprising SLC3A2 and SLC7A11, augments antioxidative responses and inhibits ferroptosis, promoting tumour growth, survival and cancer stem cell maintenance. 25 Overexpression of TXN2 has been linked to resistance against erastin/RSL3-induced ferroptosis in lung cancer cells in Xuanwei, China, 26 a region known for its high lung cancer incidence due to household smoky (bituminous) coal combustion, 27 which is a significant source of redox-active iron particles in this population. Conversely, MYH9 encodes the heavy chain of non-muscle myosin IIA, a novel cancer stem cell marker implicated in tumourigenesis via the PI3K/AKT/mTOR pathway. MYH9 is involved with a bidirectional promoter it shares with FOXE1 and PTCSC2 , suppressing promoter activity. FOXE1 is a key regulator in autophagy and matrix metalloproteinase pathways in lung cancer development, 28 while PTCSC2 is a ferroptosis-associated long non-coding RNA linked to head and neck squamous cell carcinoma. 29

The DMP cg01411366 resides within a regulatory element proximate to SLC9A10 , a member of the sodium hydrogen exchanger family implicated in transport of various substances. SLC9A10 was noted in a study on lung adenocarcinoma in never smokers, indicating a possible connection to the disease. 30 In contrast, cg12787323, located approximately 200 kb from the nearest gene, lacks enhancer–promoter interactions, complicating its interpretation. Meanwhile, cg00811020 near the Nα-acetyltransferase 30 ( NAA30 ) gene promoter is noteworthy. NAA30 encodes the catalytic subunit of N-terminal acetyltransferase complex C, essential for peptide acetylation and cellular functions such as proliferation, apoptosis and protein trafficking. Hypomethylation in the NAA30 promoter is linked to increased lung cancer risk and exposure to carcinogenic PAHs in tobacco smoke and coal combustion by-products. 31 Pathway analysis of the top DMPs suggested small GTPase-mediated signal transduction pathways play a role in lung cancer development. These GTPases, particularly K-Ras from the KRAS oncogene, are downstream mediators in the epidermal growth factor receptor (EGFR) signalling pathway, affecting cell proliferation. In East Asia, lung cancer oncogenic mutations have been identified in both EGFR (60–78% cases) and KRAS (1% cases) genes in never smokers. 32 Intriguingly, KRAS mutations correlate with PAH-rich coal combustion exposures in Xuanwei, China, 32 indicating a link between environmental factors, genetic mutations and DNAm alterations in lung cancer development.

Our findings align with previous prospective studies that used DNAm in peripheral blood cells, showing higher age-adjusted GrimAge acceleration associated with an increased lung cancer risk, 33 while other DNAm-based ageing markers showed no association. 34 GrimAge acceleration, defined as the residual from epigenetic age regressed on chronological age, includes data from 1030 CpG sites related to smoking pack-years and seven plasma proteins. 35 Remarkably, GrimAge predicts lifespan, including in never smokers, and correlates with various comorbidities. 36 Previous studies have linked GrimAge with exposure to environmental contaminants such as smoking, 37 PM 2.5 , 6 and household air pollution 38 and PAHs, 39 all are established lung cancer risk factors. 40 Participants from this study were from homogenous urban areas in Shanghai, minimising potential environmental exposure variation. Available data also suggested no significant difference in the distribution of chronic diseases, including chronic respiratory conditions at enrolment between participants who developed lung cancer and those who did not (data not presented). Future investigations with detailed exposure data are essential to clarify the environmental factors potentially influencing the GrimAge-lung cancer risk relationship observed in this study.

Our study has several strengths, including a comprehensive analysis of over 850 000 DNAm biomarkers using the Illumina Infinium EPIC BeadChip Array. This array boasts nearly twice the coverage of its predecessor, the 450 k array, used in nearly all previous prospective studies. 12–14 A novel finding of our research is that oral rinse samples, rich in epithelial cells from the upper respiratory tract directly exposed to air pollutants, could serve as non-invasive and easily obtainable specimens for DNAm analysis, particularly for diseases like lung cancer that originate from epithelial tissues. Notably, our most significant DMPs associated with lung cancer showed significant enrichment within epithelial regulatory regions. Moreover, our research is the largest prospective EWAS of lung cancer among never smokers conducted to date. We have identified DMPs with genome-wide significance, which denotes their association with future lung cancer risk in this subgroup. Nonetheless, it is vital to recognise the limitation posed by our modest sample size, which heightens the risk of false positive findings. External validation with larger cohorts is necessary to affirm the robustness and broader applicability of our findings.

Diverse epigenetic clocks have been developed, each tailored based on calibration methods, tissues, sample size and statistical approaches. We calculated epigenetic clocks using DNAm data from oral rinse samples, comprising various cell types such as buccal cells and saliva. While Horvath’s pan tissue and skin-blood clocks were developed using a variety of tissues, such as buccal cells and saliva, 41 it is important to note that none of the epigenetic clocks evaluated in our study were specifically designed for oral cell. Additionally, not all clocks demonstrated consistent accuracy across various tissue types. Despite this, we observed robust correlations between DNAm age and chronological age (Pearson’s r=0.61–0.87) in this study, suggesting the applicability of these ageing markers despite potential tissue specificity variations.

Additionally, the study followed the US Centers for Disease Control and Prevention (CDC) definition of ‘never smokers’ but did not distinguish between individuals who had never smoked and those who smoked <100 cigarettes in their lifetime. Evidence suggests minimal exposure to smoking (serum cotinine concentrations <5 nmol/L) among never smokers in a large Asian lung cancer cohort, predominantly comprising male participants. 42 Given the low smoking prevalence among Chinese women (around 2%), 43 and the high percentage of women (more than 76%) in our study, any substantive confounding due to unaccounted smoking appears unlikely. It is also notable that DNAm patterns are influenced by cumulative smoking dose and time since cessation. 44 45 While certain smoking-related DNAm signatures may persist, quitting can revert methylation levels to those resembling non-smokers. 44 45 Thus, confounding from unaccounted smoking in our cohort is expected to be negligible. Additional limitations of this study include the lack of detailed data on lung cancer histological subtypes. Since DNAm patterns vary across different histological subtypes of lung cancer, 46 future research with comprehensive histological information is warranted to identify both common and distinct DNAm patterns associated with various lung cancer subtypes.

Conclusions

In summary, our genome-wide analysis revealed multiple distinct DMPs in prediagnostic oral rinse samples from individuals who never smoked, in relation to lung cancer development. In addition, we found that an accelerated GrimAge clock was associated with an increased risk of developing lung cancer in this population. While our findings require confirmation in larger cohorts, they imply that DNAm assessment in prediagnostic oral rinse samples could offer novel insights into the risk factors and pathogenesis of lung cancer among never smokers.

Ethics statements

Patient consent for publication.

Not applicable.

Ethics approval

All study participants provided written informed consent before being interviewed, and the study protocols were approved by the institutional review boards of all participating institutions (OH98CN006).

Acknowledgments

The authors acknowledge the research contributions of the Cancer Genomics Research Laboratory of the Intramural Research Program, National Cancer Institute, National Institutes of Health for their expertise, execution and support of this research in the areas of project planning, wet laboratory processing of specimens and generating the data.

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Supplementary materials

Supplementary data.

This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.

• Data supplement 1
• Data supplement 2

X @MohammadLRahma2

MLR, CEB and X-OS contributed equally.

Presented at This research was accepted for a presentation at the 2023 Annual American Association for Cancer Research (AACR) Meeting, and an associated abstract is available in publication.

Contributors NR, QL, WZ and X-OS designed the study and supervised data collection. MLR, CB, JYYW and DAB prepared the analysis plan. MLR led data analysis and drafting the manuscript while CEB assisted in the process. MLR, CB, X-OS, JYYW, BB, AC, XW, B-TJ, WH, QC, HDH, GY, JS, JL, Y-TG, DAB, WZ, NR and QL contributed to the interpretation of the results and revision of the manuscript for important intellectual content and approved the final version of the manuscript. MLR and QL are the guarantors of this work and, as such, had full access to all the data in the study and take responsibility for the integrity of the data. WZ, NR and QL cosupervised this work. The work reported in the paper has been performed by the authors, unless clearly specified in the text.

Funding This research was supported in part by the Intramural Research Program of the National Cancer Institute, National Institutes of Health, and the National Institute of Environmental Health Sciences of National Institutes of Health (research grants R01 CA70867, CA082729, UM1 CA173640).

Competing interests None declared.

Provenance and peer review Not commissioned; externally peer reviewed.

Author note JYYW is currently at the Epidemiology and Community Health Branch, National Heart, Lung and Blood Institute. This work was conducted while formerly at the Division of Cancer Epidemiology and Genetics, National Cancer Institute.

Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

Linked Articles

• Editorial Epigenetic clock as the new hand of time for lung cancer in never smokers David C Christiani Thorax 2024; - Published Online First: 03 May 2024. doi: 10.1136/thorax-2024-221393

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