[The cluster-randomized trial].

Within the framework of a clinical trial, one is sometimes brought to randomize groups of subjects rather than the subjects themselves. This type of experimental design has methodological consequences of importance (in particular biostatistical consequences) and can limit the extrapolation of the results. A cluster randomized trial is thus justified only if the context or the question of interest imposes it and biostatistical issues have then to be handled in a rigorous way.

RCT Entities:   Population Interventions Outcomes