Differences between students in problem-based and lecture-based curricula measured by clerkship performance ratings...

Problem-based learning (PBL) is being incorporated into more medical curricula, but its influence on subsequent clinical performance remains unclear.

To determine if PBL leads to better scores for fund of knowledge or clinical problem-solving skills in required clerkships taken early in the 3rd year at Penn State College of Medicine.

Data were collected from 6 class years, for clinical clerkship subscores completed during the first 4 months of the 3rd year, of students completing 1 or 2 years in a PBL or traditional track. Clerkship scores were analyzed as individual clerkships and as the average across clerkships for each student. Statistical analysis included a comparison of clerkship scores between the 2 tracks; using a 2-sample t test, and calculation of effect sizes. A multiple regression model was also employed to adjust for age, gender, race, preadmission grade point average, and Medical College Admission Test (MCAT).

Mean scores of individual clerkships taken by problem-based or lecture-based students differed significantly in some clerkships, but the effect size was small. The effect sizes for fund of knowledge for the 6 clerkships ranged from 0.20 to 0.41; for clinical problem-solving skills, they ranged from 0.26 to 0.39. These differences between the problem-based and lecture-based students were of the same magnitude as the difference at the start of medical school on the MCAT, namely d = 0.31. There was a trend toward higher effect sizes in students having 2 rather than 1 year of PBL, and in later iterations of the track.

PBL effect size on students' scores for fund of knowledge and clinical problem-solving skills was small to moderate in various years.