Can the Publication of Case Series or Case Reports Lead to a Change in Clinical Practice?

This column provides some criteria for evaluating whether a case series or case report may warrant publication. It will emphasize the value of having biomarker data in addition to clinical data to enhance the potential validation of the report and provide ways to test the findings in randomized, controlled clinical trials (RCTs). The potential validity of the case series or report is also high if the outcome is something that would not normally be expected such as, by way of example but not limited to, sudden death or malignant hypertension in someone who had always been normotensive. Examples illustrating how case series/case reports have changed the course of clinical practice or regulatory rules governing drug approval by the US Food and Drug Administration are presented, as well as examples of how those reports have been validated by more rigorous studies including RCTs. The column also includes a discussion of situations in which case series/case reports might have an endpoint (eg, sudden death) that would not be ethical to investigate in an RCT, as well as how biomarkers have been used in such instances to avoid serious untoward outcomes for a participant while still testing the hypothesis.