• evidence-based medicine;
  • clinical trial;
  • graduate medical education;
  • internship and residency

OBJECTIVES: To measure the effectiveness of an educational intervention designed to teach residents four essential evidence-based medicine (EBM) skills: question formulation, literature searching, understanding quantitative outcomes, and critical appraisal.

DESIGN: Firm-based, controlled trial.

SETTING: Urban public hospital.

PARTICIPANTS: Fifty-five first-year internal medicine residents: 18 in the experimental group and 37 in the control group.

INTERVENTION: An EBM course, taught 2 hours per week for 7 consecutive weeks by senior faculty and chief residents focusing on the four essential EBM skills.

MEASUREMENTS AND MAIN RESULTS: The main outcome measure was performance on an EBM skills test that was administered four times over 11 months: at baseline and at three time points postcourse. Postcourse test 1 assessed the effectiveness of the intervention in the experimental group (primary outcome); postcourse test 2 assessed the control group after it crossed over to receive the intervention; and postcourse test 3 assessed durability. Baseline EBM skills were similar in the two groups. After receiving the EBM course, the experimental group achieved significantly higher postcourse test scores (adjusted mean difference, 21%; 95% confidence interval, 13% to 28%; P < .001). Postcourse improvements were noted in three of the four EBM skill domains (formulating questions, searching, and quantitative understanding [P < .005 for all], but not in critical appraisal skills [P = .4]). After crossing over to receive the educational intervention, the control group achieved similar improvements. Both groups sustained these improvements over 6 to 9 months of follow-up.

CONCLUSIONS: A brief structured educational intervention produced substantial and durable improvements in residents' cognitive and technical EBM skills.