Multicenter Trials

A multicenter trial involves two or more administratively distinct study centers, a common treatment protocol, and a leadership structure involving investigators from the different study centers. The centers are clinics, coordinating centers, and other resource centers as needed, such as central laboratories and reading centers. The complement of multicenter trial is single center trial; broadly a trial designed, conducted, and analyzed at a single site; generally absent differentiated organizational structure seen in multicenter trials. The key feature of multicenter trials is a differentiated organizational structure serving to bind centers and associated personnel into a cohesive whole. One of the obvious strengths of multicenter trials is sample size. Evidence of this is seen in table presented in this chapter for trials appearing in four major medical journals in 2006.