Clinical trials.

Clinical trials are a relatively underused form of investigation in family medicine. This paper presents an overview of those considering conducting or assessing a clinical trial. A bibliography for further reading is also provided. Topics covered include aspects of: the development of a protocol; design such as randomization and binding; the special role of non-drug studies in family medicine; measurement--especially combating bias; analysis--particularly the management of drop-outs; and, the problem of generalizability.