The Development and Evaluation of a Clinical Reasoning Case for Second-Year Medical Students.

Introduction: Clinical reasoning is a cornerstone of diagnostic and therapeutic decision-making, yet it is infrequently taught in preclinical medical education and is often taught implicitly. Methods: To address this gap, we developed a clinical reasoning case focused on hematochezia as part of a year-long longitudinal clinical reasoning course for second-year preclinical medical students. The session combined large-group instruction with small-group learning activities that emphasized core reasoning skills, including problem representation, illness scripts, differential diagnoses, and diagnostic and management planning. A pre- and postintervention survey measured changes in students' confidence and attitudes about clinical reasoning skills and concepts and knowledge of hematochezia. Results: Of the 123 medical students who attended the case, 92 completed both surveys (74.8% response rate). Confidence improved significantly in all domains ( Discussion: Integrating formal clinical reasoning instruction into preclinical medical education through case-based learning is an effective strategy for teaching second-year medical students essential clinical reasoning skills.