Teaching medical decision analysis: the hepatitis B vaccine.

The process of formal decision analysis is illustrated by using the case of the hepatitis B vaccine in a computer program designed to teach both subjects to medical students. The software presents the medical facts, determines personal risks, allows input of personal values and calculates utilities for the various branches of the decision tree. There are three possible choices: vaccinate; screen first for antibodies against the hepatitis B virus and vaccinate only if negative; and wait (do not vaccinate). The decision with the utility of the highest numerical value is assumed to be the best under the given set of circumstances. Unlike commercial packages, this software contains the information internally and does not require that the user be familiar with either medical decision analysis or with the medical aspects of hepatitis. The program is available for PC's.