Decision analysis in medicine.

Introduction For many straightforward medical problems any well trained doctor will make a good decision. Sometimes the correct course of action is unclear, however, and without help doctors and patients may make poor decisions because of a failure to consider probabilities correctly or to recognise the range of patients' values and weigh these correctly. Wrong decisions are made as a result of well recognised biases,' and one way of avoiding these biases and clarifying the problem is decision analysis.2 I Decision analysis is a method for breaking complex problems down into manageable component parts, analysing these parts in detail, and then combining them in a logical way to indicate the best course of action. In North America decision analysis is taught in most undergraduate medical courses but it is rarely used in the United Kingdom and was omitted from a BMJ series on logic in medicine in 1987.4 With more emphasis than ever before being put on patient choice in the NHS the time is ripe for a change of heart on decision analysis and we hope to go some way to remedy this national neglect in this article.