Development and Evaluation of a Problem-Based Learning Case Repository for Clinical Molecular Microbiology Education: A Randomized Controlled Trial

Background Traditional didactic teaching in medical laboratory science often inadequately prepares students for the complexities of modern molecular diagnostics. This study aimed to develop and evaluate a systematic problem-based learning (PBL) case repository for clinical molecular microbiology education to enhance students' practical competencies and clinical reasoning skills. Methods We developed a hierarchical case repository comprising 28 authentic clinical cases organized into four progressive modules: PCR technology fundamentals, next-generation sequencing applications, antimicrobial resistance detection, and emerging pathogen identification. A single-center randomized controlled trial was conducted with 20 fourth-year medical laboratory science students randomly allocated to either PBL case-based instruction (n = 10) or traditional lecture-based instruction (n = 10). The 16-week intervention was evaluated using a comprehensive multidimensional assessment framework including theoretical examinations, practical skills testing, clinical reasoning evaluation, innovative thinking assessment (Torrance Tests of Creative Thinking), learning autonomy scale, 6-month knowledge retention test, and clinical internship performance ratings. Results Students in the PBL group demonstrated significantly superior outcomes across all assessment domains. Theoretical examination scores (mean ± SD) were 86.7 ± 8.2 vs 79.4 ± 9.6 ( P  < 0.01), practical skills assessments 92.3 ± 5.7 vs 84.6 ± 7.9 ( P  < 0.001), and clinical reasoning abilities 42.6 ± 4.8 vs 35.2 ± 6.3 ( P  < 0.001) for PBL and control groups, respectively. Post-intervention innovative thinking scores increased to 126.7 ± 12.4 in the PBL group versus 108.9 ± 14.6 in controls ( P  < 0.001). Learning autonomy was rated 4.3 ± 0.5 vs 3.4 ± 0.6 ( P  < 0.001) on a 5-point Likert scale. Six-month knowledge retention rates were 82.6% vs 68.4% ( P  < 0.001), while clinical internship performance ratings were 4.4 ± 0.5 vs 3.7 ± 0.7 ( P  < 0.001). Student satisfaction with the PBL approach reached 4.6 ± 0.4 (5-point scale). Conclusions This case-based PBL approach appears to bridge the theory-practice gap in molecular diagnostics education by integrating authentic clinical scenarios with progressive complexity. It was associated with improvements in students' theoretical knowledge, practical skills, clinical reasoning, and innovative thinking. These preliminary findings suggest potential benefits for implementing PBL in medical laboratory education and provide a framework for further development to cultivate competent professionals in evolving healthcare contexts, though larger studies are needed to confirm generalizability.