B – Cluster randomized trials

Meurer WJ, Lewis RJ. Cluster randomized trials evaluating treatments applied to groups. JAMA 2015;313(20):2068-2069
(doi: 10.1001/jama.2015.5199)

Sometimes a new treatment is best introduced to an entire group of patients rather than to individual patients. One approach to evaluate the efficacy of such treatments is to conduct a cluster randomized trial. According to the authors, four points are to be considered when evaluating a cluster randomized trial. Among them, was the use of clustering well justified? Was the intracluster correlation appropriately accounted for in the design, analysis, and interpretationm of the trial?