You’ve searched and reviewed the literature on your research topic, designed your study accordingly, and now you’re ready to write up your results in a manuscript for submission to a peer-reviewed journal. In the Introduction and Discussion sections of the manuscript, you will need to cite the previously published studies.

Specifically, in the Introduction, you’ll need to provide background on the existing literature, to impart context and perspective on what is known in your field and – more importantly – where the gaps in knowledge are, and how your study addresses those gaps. You’ll need to provide sufficient detail about the previous studies to make a clear, concise argument for the importance of your study and the value that its results will add to this area of study. However, the material should be kept brief, as the Introduction is generally limited to a couple of paragraphs.

In the Discussion, you’ll cite previous studies and compare and contrast their results with those of your study. Were outcomes similar? If so, is it because your and their studies were conducted in a similar manner, or is it despite differences in methodology or patient populations? Were outcomes different? If so, describe how the previous study was different with respect to the methodology or patient population and provide potential reasons for the observed difference.

The single sentence in the Introduction, or the opening sentence of a paragraph in the Discussion that describes a previously published study, should open with a description of the type of study that was conducted:

In a Level I study by Author 1 and Author 2, …
In a randomized, controlled trial of …
In a prospective cohort study …
Author et al. retrospectively evaluated …
In a retrospective chart review, …

This key information allows the reader to evaluate the quality, rigor, and generalizability of the cited study’s results. Surprisingly, sometimes this information is not readily apparent in the Abstract, and one needs to go the Methods of the full paper to discern what was actually done.

Which brings me to my next point: One must ALWAYS read the full paper if citing it, to ensure that all of the details are presented accurately and in the correct context in your manuscript. The abstract only presents the most important points of the study, as decided by the authors. When you review the full paper, you may discover some “small” details, such as inclusion or exclusion criteria or differences in methodology or analysis, that have a profound impact on how comparable their results are to yours.

Also, remember that the reviewers of your manuscript will likely be experts who are very familiar with your research topic; they’ll notice if a previous study is not described accurately.

Ok, you’ve finished the first comprehensive draft of your manuscript and are ready to send it to your coauthors for their input. Before doing so, conduct another literature search to cover the last 12 to 18 months to ensure that the cited literature in your paper is up to date with what’s been published on your research topic.

I hope you’ve found these suggestions helpful. Next week we’ll discuss the finicky formatting details for correctly citing the literature.

I look forward to receiving your feedback, and I welcome suggestions for future weekly writing tips.