Perils of evidence-based medicine.
Evidenced-based medicine views random-assignment clinical trials as the gold standard of evidence. Because patient populations are heterogeneous, large numbers of patients must be studied in order to achieve statistically significant results, but the means or medians of these large samples have weak predictive validity for individual patients. Further, the logic of random-assignment clinical trials allows only the inference that some subset of patients benefits from the treatment. Post-hoc analysis is therefore necessary to identify those patients. Otherwise, many patients may receive treatments that are useless and potentially harmful.
Williams
Ben A
BA
Department of Psychology, University of California-San Diego, La Jolla, CA 92093-0109, USA. bawilliams@ucsd.edu
D015982:Bias; D017326:Clinical Trials, Phase III as Topic; D003627:Data Interpretation, Statistical; D019317:Evidence-Based Medicine; D006801:Humans; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic; D018401:Sample Size; D016896:Treatment Outcome