Donner – Design &&& Analysis of Cluster Randomization Trials

A cluster randomization trail is one in which intact social units, or clusters of individuals, are randomized to different intervention groups. Trials randomizing clusters have become particularly widespread in the evaluation of non-therapeutic interventions, including lifestyle modification, educational programs and innovations in the provision of health care. The units of randomization in such studies are diverse, ranging from relatively small clusters such as families or households, to entire