Characteristics of Cluster Randomized Trials: Are They Living Up to the Randomized Trial?

JAMA: January 21, 2013

Cluster randomized control trials (RCTs) are a form of prospective study where groups of individuals are allocated to an intervention. They offer the unique advantage of rigorously evaluating practices that cannot feasibly be randomized to the individual—such as public health or quality programs.1 While cluster RCTs can test questions traditional RCTs cannot, the design requires more participants to achieve equivalent statistical power.1 Over the last decade, the number of cluster RCTs have grown dramatically,2 but some researchers remain uncertain of how to interpret this study design. Read more