Planning and implementation of large clinical trials

The large-scale collaborative clinical trial has become an important activity in the biomedical research spectrum. It is the clinical trial that determines most precisely the efficacy of treatment of preventive regimens. These large studies, which usually cost tens of millions of dollars and use large numbers of research facilities, have a major impact on research and medical practice. Consequently, it is required that a number of factors be carefully assessed before any such study is undertaken. A formalized decision process has been developed by the National Heart, Lung and Blood Institute to aid in the formulation, design, conduct, analysis and dissemination of the results of clinical trials. This decision process, which provides a planning framework for the trial, is described here. The framework is constructed around three major decision points at which resources are committed: to plan the trial, to conduct the trial, and to terminate and disseminate the results of the trial.