Context Physicians depend on the medical literature to keep current with clinical information. Little is known about residents' ability to understand statistical methods or how to appropriately interpret research outcomes. Objective To evaluate residents' understanding of biostatistics and interpretation of research results. Design, Setting, and Participants Multiprogram cross-sectional survey of internal medicine residents. Main Outcome Measure Percentage of questions correct on a biostatistics/study design multiple-choice knowledge test. Results The survey was completed by 277 of 367 residents (75.5%) in 11 residency programs. The overall mean percentage correct on statistical knowledge and interpretation of results was 41.4% (95% confidence interval [ Cl], 39.7%-43.3%) vs 71.5% ( 95% Cl, 57.5%-85.5%) for fellows and general medicine faculty with research training ( P <. 001). Higher scores in residents were associated with additional advanced degrees (50.0% [ 95% Cl, 44.5%-55.5%] vs 40.1% [ 95% Cl, 38.3%-42.0%]; P <. 001); prior biostatistics training (45.2% [ 95% Cl, 42.7%-47.8%] vs 37.9% [ 95% Cl, 35.4%40.3%]; P=.001); enrollment in a university-based training program (43.0% [ 95% Cl, 41.0%-45.1%] vs 36.3% [ 95% Cl, 32.6%-40.0%]; P=.002); and male sex (44.0% [ 95% Cl, 41.4%-46.7%] vs 38.8% [ 95% Cl, 36.4%-41.1%]; P=.004). On individual knowledge questions, 81.6% correctly interpreted a relative risk. Residents were less likely to know how to interpret an adjusted odds ratio from a multivariate regression analysis (37.4%) or the results of a Kaplan-Meier analysis (10.5%). Seventy-five percent indicated they did not understand all of the statistics they encountered in journal articles, but 95% felt it was important to understand these concepts to be an intelligent reader of the literature. Conclusions Most residents in this study lacked the knowledge in biostatistics needed to interpret many of the results in published clinical research. Residency programs should include more effective biostatistics training in their curricula to successfully prepare residents for this important lifelong learning skill.
