ABSTRACT: BACKGROUND: Few studies have examined residents' retained knowledge and confidence regarding essential evidence-based medicine (EBM) topics. OBJECTIVE: To compare postgraduate year-3 (PGY-3) residents' confidence with EBM topics taught during internship with that of PGY-1 residents before and after exposure to an EBM curriculum. METHODS: All residents participated in an EBM curriculum during their intern year. We surveyed residents in 2009. PGY-1 residents completed a Likert-scale type survey (which included questions from the validated Berlin questionnaire and others, developed based on input from local EBM experts). We administered the Berlin questionnaire to a subset of PGY-3 residents. RESULTS: Forty-five PGY-3 (88%; n = 51) and 42 PGY-1 (91%; n = 46) residents completed the survey. Compared with PGY-1 residents pre-curriculum, PGY-3 residents were significantly more confident in their knowledge of pre- and posttest probability (mean difference, 1.14; P = .002), number needed to harm (mean difference, 1.09; P = .002), likelihood ratio (mean difference, 1.01; P = .003), formulation of a focused clinical question (mean difference, 0.98; P = .001), and critical appraisal of therapy articles (mean difference, 0.91; P = .002). Perceived confidence was significantly lower for PGY-3 than post-curriculum PGY-1 residents on relative risk (mean difference, -0.86; P = .002), study design for prognosis questions (mean difference, -0.75; P = .004), number needed to harm (mean difference, -0.67; P = .01), ability to critically appraise systematic reviews (mean difference, -0.65, P = .009), and retrieval of evidence (mean difference, -0.56; P = .008), among others. There was no relationship between confidence with and actual knowledge of EBM topics. CONCLUSIONS: Our findings demonstrate lower confidence among PGY-3 than among PGY-1 internal medicine residents for several EBM topics. PGY-3 residents demonstrated poor knowledge of several core topics taught during internship. Longitudinal EBM curricula throughout residency 5 help reinforce residents' EBM knowledge and their confidence.
