Problem- vs. lecture-based pharmacology teaching in a German medical school.

We have compared the effectiveness of problem-based learning (PBL) and classical lecture-based learning (LBL) in conveying medical facts in a general pharmacology class of third year medical students ( n=107). Three groups with a total of 31 students were randomly assigned to PBL. The PBL groups (9-12 students each) received ten 2-h sessions in which a clinical case was discussed and ten 2-h sessions in which areas of pharmacology not covered by the case discussions were presented in an LBL format (one group with all 31 students). The other students were assigned to groups of 14-15 students and received 20 2-h sessions in an LBL format. At the end of the semester all students received a questionnaire and participated in the same 30-question multiple-choice exam. The mean number of false answers was 7.6+/-4.0 and 9.7+/-4.7 in the PBL and LBL groups, respectively ( P<0.05 in a two-tailed t-test), and the percentage of failing students (>10 false answers) was 27% and 38%, respectively. Both groups were asked to rate their pharmacology class on a scale of 1 (lowest) to 10 (highest). In this questionnaire, PBL students by average rated generated interest in pharmacology, conveyed knowledge in pharmacology and understanding of medical questions approximately 1 point higher than LBL students. In an additional questionnaire given to the PBL students only, they reported to have prepared themselves 0.9+/-1.1 h for their lecture sessions but 3.0+/-1.4 h for their case discussions. The above findings were largely confirmed in the next semester when students were allowed to decide whether to participate in PBL or LBL classes. Moreover, PBL students did not score worse than LBL students in nation-wide pharmacology exams (523+/-76 vs. 500+/-91 points, P=0.09). We conclude that a switch from LBL to PBL teaching of pharmacology does not occur at the expense of factual knowledge transmission.