The discussion of case reports in the current
JMLA case study focuses on the relevance of the cases to the question being examined. What else should you consider in evaluating the "quality" of a case report?
As mentioned in a
previous post about the new Journal of Medical Case Reports, case reports serve a number of key functions in understanding disease diagnosis and therapy, as well as potential side effects of diagnostic or therapeutic interventions.
A good case report tells the "story" of a particular patient's case (or a small group of patient's case), in a temporal sequence and with enough detail to describe for the reader how the case unfolded, what diagnostic tests and/or therapies were employed, the process of differential diagnosis, and the outcome of the case.
Case reports are generally narrative, but are still subject to the basic principles of the
scientific method -- they must tell us how the authors went through the process of understanding what was "going on" in the patient's case, how the patient was evaluated and treated, and what the outcome was, all the while stressing the "evidence" for the authors' conclusions. A case report provides a real-world example of how clinicians formulate and test hypotheses in a clinical scenario.
In their instructions for medical students interested in drafting case reports, Anwar et al. advise that a case report "should read like an interesting story, which your reader should enjoy." (
How to write a case report, Student BMJ, 2004 Feb, 12:60-1.) . These authors recommend a case report format that includes an introduction, the case itself (history, clinical features, investigations, treatment and outcome, progress of the case), discussion with literature review, key message the report is trying to convey, and any recommendations based on the authors' experience with the case.
In looking at the cases for this month's question, there is some variability in the amount of detail provided (e.g. some articles report how long the patient had the ileostomy before diarrhea developed while others don't). Sorinola et al examined instructions for authors from 163 core medical journals that publish case reports, and note that the journals' instructions generally focused on style (which sections the case should be divided into, how many illustrations were allowed) rather than content (originality, instructive content, innovation, unusual/rare disease). Interestingly, instructions noted the role of a case report for hypothesis generation in only 9 of the titles (6%).
Table 2 of this study also includes a suggested checklist for case report content, based on the investigators' examination of journal instructions to authors, that may also be useful in evaluating case report content:
Reference: Sorinola O, Olufowobi O, Coomarasamy A, Khan KS. Instructions to authors for case reporting are limited: a review of a core journal list. BMC Med Educ. 2004 Mar 25;4:4. (PubMed record with link to full-text in PubMed Central)One basic question likely underlies any evaluation of a case's relative quality for a particular topic: Does the case provide enough detail, organized appropriately, to understand the steps that the author too, in evaluating and treating the patient, and the eventual outcome/prognosis for the case? For the C. difficile question explored in this month's case study, a good case report would then include:
- a discussion of when the ileostomy was placed and when the diarrhea developed
- description of the patient's immediate history around the time the persistent diarrhea developed (e.g. recent antibiotic therapy); in-patient vs. out-patient development of symptoms?
- duration of the diarrhea and volume of output from the ileostomy
- differential diagnosis - did the authors suspect issues other than C. diff infection? How did they arrive at the diagnosis of C. diff as a causative organism?
- treatment and outcome, including antimicrobial therapy, any operative intervention required, prevention of complications of diarrhea, how long it took the symptoms to resolve, length of hospital stay, any associated complications, final outcome of the patient case
And finally, for a question like this for which the evidence seems quite rare, the authors' connection between their case and related literature on the topic (with possible review of reported cases) proves very useful in verifying that your literature search was effective in identifying all of the relevant literature.
Related links:-
Judging criteria from a Navy student case report competition (links to Word document) -- another suggested format for case report structure, with guidance in how to assess quality for each section
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Ch. 10: Case reports etc., excerpt from
Iles's Guidebook to better medical writing -- suggestions for authors interested in publishing case reports
Labels: case reports
