Presenting clinical pharmacology and therapeutics: evaluation of a problem based approach for choosing drug treatments.

Between 1983 and 1989 three studies were conducted to determine whether the ability of senior medical students to choose drug treatments rationally had improved. This period spanned the implementation of a course in pharmacotherapeutics which trained students to use a systematic problem-based approach to choosing and prescribing drugs. The results show that in the short-term students remembered how to choose drugs rationally for cases known to them (retention effect), but had difficulties in transferring what had been learned to similar but different problems (transfer effect). In the medium-term a retention effect was shown for all three aspects of choice (drug, dosage and duration), and a transfer effect for choosing a dosage and duration when solving almost all types of patient problems used in the study. Transfer of the ability to choose a drug was less easily demonstrable. Compared with control students rational choices of trained students increased significantly for all aspects of drug choice, and almost all patient problems used in the study, whether or not they had been discussed. Possible causes for not finding a full transfer effect are: the intervention (course) may have been too short; there was sufficient knowledge about drugs but a lack of understanding of basic pharmacological concepts; or there was no reinforcement of the problem-based approach during clinical clerkships.