Teaching in small portions dispersed over time enhances long-term knowledge retention

Objective: A prospective interventional study design was used to investigate our research question: Does a dispersed curriculum promote better short- and long-term retention over a massed course? Methods: Participants included 20 gastroenterology residents from the University of Calgary (N = 10) and University of Toronto (N = 10). Participants completed a baseline test of nutrition knowledge. The nutrition course was imparted to University of Calgary residents for 4 h occurring 1 h weekly over 4 consecutive weeks: dispersed delivery (DD). At the University of Toronto the course was taught in one 4h academic half-day: massed delivery (MD). Post-curriculum tests were administered at 1 week and 3 months to assess knowledge retention. Results: The baseline scores were 46.39 +/- 6.14% and 53.75 +/- 10.69% in the DD and MD groups, respectively. The 1 week post-test scores for the DD and MD groups were 81.67 +/- 8.57%, p < 0.001 and 78.75 +/- 4.43, p < 0.001 which was significantly higher than baseline. The 3-month score was significantly higher in the DD group, but not in the MD group (65.28 +/- 9.88%, p = 0.02 vs. 58.93 +/- 12.06%, p = 0.18). The absolute pre-test to 1-week post-test difference was significantly higher at 35.28 +/- 7.65% among participants in the DD group compared to 25.0 +/- 11.80% in the MD group, p = 0.048. Similarly, the absolute pre-test to 3-month post-test difference was significantly higher at 18.9 +/- 6.7% among the participants in the DD group, compared to 6.8 +/- 11.8% in the MD group, p = 0.021. Conclusions: Long-term nutrition knowledge is improved with DD compared with MD.