Teaching residents evidence-based medicine skills: a controlled trial of effectiveness and assessment of durability

Abstract

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.

FIGURE 1

Study design and timetable.

FIGURE 2

Test scores for the precourse test and the three postcourse tests by experimental group. The gray squares represent the mean test scores in the experimental group for each test with 95% confidence intervals. The black circles represent the mean scores for the control group with 95% confidence intervals.