Effect of Interpolated Questions on Podcast Knowledge Acquisition and Retention: A Double-Blind, Multicenter, Randomized Controlled Trial

Abstract

Study objective: We determine whether interpolated questions in a podcast improve knowledge acquisition and retention.

Methods: This double-blinded controlled trial randomized trainees from 6 emergency medicine programs to listen to 1 of 2 versions of a podcast, produced de novo on the history of hypertension. The versions were identical except that 1 included 5 interpolated questions to highlight educational points (intervention). There were 2 postpodcast assessments, 1 within 48 hours of listening (immediate posttest) and a second 2 to 3 weeks later (retention test), consisting of the same 15 multiple-choice questions, 5 directly related to the interpolated questions and 10 unrelated. The primary outcome was the difference in intergroup mean assessment scores at each point. A sample size was calculated a priori to identify a significant interarm difference.

Results: One hundred thirty-seven emergency medicine trainees were randomized to listen to a podcast, 69 without interpolated questions (control) and 68 with them (intervention). Although no significant difference was detected at the immediate posttest, trainees randomized to the interpolated arm had a significantly higher mean score on the retention test, with a 5.6% absolute difference (95% confidence interval 0.2% to 10.9%). For the material covered by the interpolated questions, the intervention arm had significantly higher mean scores on both the immediate posttest and retention tests, with absolute differences of 8.7% (95% confidence interval 1.6% to 15.8%) and 10.1% (95% confidence interval 2.8% to 17.4%), respectively. There was no significant intergroup difference for noninterpolated questions.

Conclusion: Podcasts containing interpolated questions improved knowledge retention at 2 to 3 weeks, driven by the retention of material covered by the interpolated questions. Although the gains may be modest, educational podcasters may improve knowledge retention by using interpolating questions.