How to read a case report (or teaching case of the month)

Case reports are of minor importance in evidence-based medicine but can nonetheless make meaningful contributions to both knowledge and education. Although many traditional medical journals publish fewer case reports in this era of space constraints and preoccupation with Impact Factors, new Internet-based journals are appearing that focus exclusively on reports of individual cases. Given the variability of documentation, objectivity, and interpretation among the case reports now accessible by clinicians and trainees, it is important to be able to read them critically and to use the information they contain appropriately. This article discusses factors to consider in evaluating individual case reports, and provides a practical semi-quantitative scheme for assessing their potential validity and educational value.