Part V: Dissecting a Scientific Research Paper — Discussion and Conclusion
In our final post of this educational series, we will work through the Discussion section and last remaining pieces of the manuscript “Smoking Cessation, Weight Change, Type 2 Diabetes, and Mortality”.
The Discussion section is my favorite part of a manuscript. We’ve worked hard to get to this point — wading through the dense methods, statistical analyses, and technical explanation of the results. Now we get to answer the question — “what does it all mean?!”.
The Discussion section is the place where the researchers discuss and interpret their results for the reader. They typically provide an explanation of how these findings fit into what is currently known about the topic, by calling on additional papers and research studies. The authors then let us know how their study findings contribute or make an impact on that topic. This section will often include qualities that make this study and the results reliable, as well as a description of the study’s limitations.
The Discussion section begins by summarizing the main study findings: the researchers “observed a temporary elevation in the risk of type 2 diabetes after smoking cessation, primarily among quitters who gained weight” (p. 629). We learn that these findings are similar to what other research studies have found. The researchers mention that their findings show that an increase in weight within 6 years of quitting smoking “explained 68.4% of the increase risk of type 2 diabetes” (p. 630). Meaning, gaining weight was the primarily reason why people who quit smoking had a higher risk of developing type 2 diabetes!
The authors found that while there was an increase in type 2 diabetes risk, the risk of dying from any cause and from cardiovascular-related reasons actually decreased in people who quit smoking, even among those who gained weight. Again, these findings appear to be similar to what other studies have found.
Overall, the study findings showed that gaining weight after quitting smoking did not lessen the benefits of quitting on cardiovascular mortality or life expectancy. The researchers then briefly discuss the different ways that have been shown to improve diet and increase exercise, leading to a reduction in the amount of weight gained after quitting smoking.
The authors mention some of the limitations of the study — these are aspects of the study that may limit how valid the findings are. They note the following: potential misclassifications of data, missing data, and limited generalizability of the findings — meaning the findings of this study may not apply in other contexts. The participants in this study included mainly Caucasian health professionals without major chronic diseases when they first started participating. Therefore, these findings may not be able to be reproduced in other groups of people in different settings. For example, if we conducted this same study with low income, young adults in rural South America — we might not get the same findings.
And lastly, the authors wrap-up the article in a concluding sentence (rather than a separate conclusion section) by restating the main findings and “takeaway”: “In conclusion, our findings suggest that a temporary increase in the risk of type 2 diabetes due to weight gain after smoking cessation did not attenuate the benefits of smoking cessation on reducing total and cardiovascular mortality”(p. 631–2).
After completing the main manuscript, you’ll likely see these other sections which are common in a manuscript:
- References — The authors and studies referred to throughout the article.
- Supplemental materials — Extra tables, graphs, data collection instruments (questionnaires, etc.) are found here.
- Acknowledgements — The authors may acknowledge those who have contributed to the research and/or manuscript in some way, including the study participants.
- Funding source — This explains how the study was funded (who provided the money for the study and the corresponding grant/award number)
- Competing interests/Conflicts of interest — Authors must disclose in writing if they have any competing interests (something that may influence the legitimacy of the research).
- Author details — This explains the ways in which the authors contributed to the research and manuscript.
- Ethics approval — An acknowledgement that the research was approved by an Institutional Review Board (IRB) — an entity that oversees human subjects research.
What do we do with these findings? A good place to start after reading any newly published research on a relevant medical condition is to talk with your doctor about what this means for you.
We did it! We made it through a scientific manuscript in its entirety.
I hope you’ve enjoyed this educational series and learned some helpful information on how to go about reading through a manuscript on your own. What other educational topics are you interested in? Suggest an idea or topic to our team at ResearchMatch by commenting below!
ResearchMatch is here to help educate and empower our volunteers to take part in clinical trials and research studies. This includes understanding how their participation makes a difference and contributes to scientific discoveries. Interested in joining ResearchMatch? Click here to sign-up as a volunteer and be “matched” with research studies that are of interest to you!
Reference:
Hu Y, Zong G, Liu G, Wang M, Rosner B, Pan A, Willett WC, Manson JE, Hu FB, Sun Q. Smoking cessation, weight change, type 2 diabetes, and mortality. N Engl J Med 2018;379(7):623–632: doi: 10.1056/NEJMoa1803626.
Access all the articles in this educational series by clicking below:
