[The influence of biographical details in case reports on diagnostic judgment]

Diagnostic judgment of medical students is influenced by patients they have seen recently. Not only signs and symptoms but also biographic data of the demonstrated patient contribute to this phenomenon. In this study the question is raised whether practising physicians are susceptible to the same influence after reading a case report in a medical journal. A case to be published in this journal was transformed into two patient scripts. The first was based on the same diagnosis and the same signs and symptoms, the second was based on another diagnosis and contained partly similar partly different signs and symptoms. Both scripts contained the same, striking biographic data derived from the original case report. One of the two scripts was presented randomly to a control group of 53 practising doctors before the date of publication. They were asked to rate the probability of 8 diagnoses on a 7-point scale. The experimental group consisted of 16 doctors who stated having read the case report. The scores of both groups were compared using analysis of variance. The experimental group in both cases assigned a significantly higher probability to the diagnosis of the published case report. In the first case they were right, in the second they were wrong. These results are similar to the findings with medical students. The question to be explored further is how to present patient cases in medical education. On one hand they should be attractive with some real life data, on the other hand spectacular biographic data may impair the diagnostic process.