Friday, May 30, 2008

Case Reports: Why We Need Them

Case reports get the short end of the stick. In our evidence-based world, we know that the case report is often seen as slightly more useful than an anecdote; we have all seen evidence hierarchies which place the case report low on the "level of evidence" scale. But the importance of a case report cannot be overestimated. Let me demonstrate this by noting the following tale: early in 1981 an initial case report of a young man with a rare form of cancer was printed in a leading medical journal. What was unusual in this case was the presence of Kaposi’s sarcoma, which traditionally had been associated with older, immune-compromised patients. To see this in a young person was certainly noteworthy. That single paper signaled the onset of the today’s AIDS crisis, and led later that year to report in the Lancet detailing this finding in a larger number of individuals (1). All from a single case report.

The point of placing the case report lower on the evidence hierarchy is to recognize that we cannot generalize the findings from a single case to a larger population. To do that, we would need a clinical trial. But that does not mean case reports have no value. From my perspective, it is important for the chiropractic profession to document the full breadth and depth of what it does. It is simply not possible, either financially or logistically, to implement and conduct a clinical trial for every conceivable condition chiropractors treat. But a well-written case report can provide guidance for clinicians grappling with managing conditions that are outside their daily norm. In my former role as journal editor, I spent a significant amount of time doing outreach to the clinical chiropractic community- field practitioners and faculty clinicians- to entice them into considering preparing case reports. As far back as 1991, I reported on my success in doing so (2). Even today, with the huge growth in evidence-based practice, I think a good case report has value, so long as we understand its limitations.

To those in clinical practice, to those who act as our faculty clinicians, the question I have is: have you seen an interesting case? Something that was unusual and therefore educational? It might be an unusual diagnosis not normally seen in a chiropractic setting, or perhaps it was an unusual response to therapy. If so, why not consider writing it up? Let me know and I can help you do so. Give it a shot, why don’t you?

1. Hymes, K.B., Greene, J. B., Marcus, A., et al. Kaposi's sarcoma in homosexual men: A report of eight cases. Lancet 1981;2:598-600
2. Lawrence DJ. Fourteen years of case reports. J Manipulative Physiol Ther 1991;14:447-449

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