[Do physicians interpret therapy outcome differently than students?]

Abstract

Results are presented in the most varied ways in medical publications and advertising material. The reader should be able to interpret the results of such studies accurately. In the present investigation our interest focused on whether a physician learns to analyse results correctly in medical school or in his subsequent clinical career. We also investigated whether the interpretation of therapeutic data differs as between students in the 4th year of medical school, students of the 6th year and physicians. In a questionnaire, one result from the Helsinki Heart Study was presented in for different ways: (a) absolute risk reduction, (b) relative risk reduction, (c) NNT (number needed to treat) and (d) percentage of patients without a cardiovascular event during the monitoring period. To each group we assigned a different drug. We interviewed students in the 4th and 6th years of medical school, physicians during a continuing education course and physicians before and after an evidence-based medicine (EBM) course. They replied by stating which drug they would select for therapy. Evaluation of the questionnaire showed that the majority regarded the drug for relative risk reduction as the most effective. Physicians taking part in the EBM course analysed the statistical data better than the other groups interviewed, and their answers even improved significantly after the EBM course. There was no difference in the interpretation of therapeutic results between students and physicians who had not taken part in an EBM course. The study also found that in all the groups interviewed the presentation of the results of scientific studies has a marked influence on their interpretation. We conclude that interpretation of medical studies should form part of every student's and physicians's training, either in medical school or continuing education courses. On the other hand, the results of studies should be uniformly expressed in absolute figures, to make it easier to compare different results.