Peer instruction in preclinical osteopathic microbiology education: a single-group pre–post quasi-experimental study of short-term performance outcomes and student perceptions

BACKGROUND: Peer instruction (PI) is an active learning strategy grounded on social learning theory that promotes engagement and conceptual understanding through structured peer discussion. Although implemented widely in undergraduate science education, its application in osteopathic medical education remains underexplored. OBJECTIVE: This study examined associations between PI and short-term performance outcomes as well as student perceptions of PI among first-year osteopathic medical students in a preclinical microbiology course. METHODS: A single-group pre-post quasi-experimental study without a control group was conducted simultaneously across both campuses of Burrell College of Osteopathic Medicine during a synchronized single 2-hour session titled 'Infections that affect the nervous system' in April 2025. Of 295 eligible students, 218 consented and completed all study components: PI activity involving 10 clinical based questions, a five-question exit quiz, and a post-session feedback survey on students' perception. The PI activity included individual polling, peer discussion, re-polling, student explanation, and faculty review. Data was analyzed using IBM SPSS (version 30.0). RESULTS: Post-PI scores (6.57 ± 1.72) were significantly higher than pre-PI scores (4.46 ± 1.75; yielding a mean gain of 2.11 points (95% CI: 1.88-2.34; t(217) = 18.18, p 0.05). Exit quiz scores (mean = 3.44 ± 1.18) correlated positively with both pre- and post-PI scores (Pearson correlation, r = 0.29 and 0.28; p < 0.001). Survey responses indicated favorable perceptions: 69.7% reported improved understanding, 61% rated the session good or excellent and 54.6% recommended PI for future courses. CONCLUSION: PI was associated with improved short-term performance outcomes and favorable student perceptions in a preclinical osteopathic microbiology course. These findings support the feasibility and potential educational value of PI as a promising active learning strategy in osteopathic medical education. Future research should explore longitudinal outcomes, controlled comparisons, and multi-institutional replication.