Integration of problem-based learning and flipped classroom for teaching hypertensive disorders of pregnancy: an ADDIE model-based iterative improvement study

Abstract Objectives To evaluate an analysis, design, development, implementation, evaluation (ADDIE)-guided integration of problem-based learning (PBL) and flipped classroom teaching for hypertensive disorders of pregnancy (HDP) in an obstetrics clerkship. Methods A three-phase PBL-flipped classroom module was developed and implemented in accordance with the ADDIE model, enrolling 75 obstetrics clerkship students between November 2025 and February 2026. Following delivery to the first two batches (n=30), five targeted refinements were made to the module before it was administered to the subsequent three batches (n=45). The primary outcome was knowledge gain, assessed using paired t -tests and the Wilcoxon signed-rank test and reported as medians with interquartile ranges (Q1–Q3). Secondary outcomes included satisfaction and faculty team performance ratings. Results Knowledge scores increased markedly from pre-test to post-test, with a mean improvement of 71.20 points (standard deviation [SD] = 24.88) (paired t -test and Wilcoxon signed-rank test, both p<0.001), representing a large within-subject effect size. Significant gains were observed across all five domains after Bonferroni correction (p<0.001). The two-sided 95 % confidence interval ( CI ) for mean paired score improvement was 65.5–76.9 points (degrees of freedom [df]=74). Mean satisfaction was 94.67/100.00, and 80 % of small groups achieved scores of ≥18/20 for participation and guideline use. Conclusions A tool-anchored PBL approach combined with flipped classroom preparation was associated with larger short-term knowledge gains and high student satisfaction. ADDIE-guided iterative revisions led to observable improvements in teamwork and feedback processes, however, between-batch differences in knowledge scores were not statistically significant, suggesting that these iterations primarily reflect process refinement rather than measurable learning gains. Larger comparative trials are warranted to further evaluate the effectiveness of this approach.