Multisite clinical trials in alcoholism treatment research: organizational, methodological and management issues.

Multisite clinical trials have two major advantages over single-site studies: the large sample size of multisite studies allows for adequate statistical power and better representativeness of the population being studied. However, they are more complex to implement than single-site studies. This article reviews previous multisite clinical trials of alcohol abuse and alcoholism, reasons for selecting a multisite design, management of such studies, and some statistical issues.