title: Challenges of cluster randomized trials.
abstract: Cluster randomized trials are trials that randomize clusters of people, rather than individuals. They are becoming increasingly common. A number of innovations have been developed recently, particularly in the calculation of the required size of a cluster trial, the handling of missing data, designs to minimize recruitment bias, the ethics of cluster randomized trials and the stepped wedge design. This article will highlight and illustrate these developments. It will also discuss issues with regards to the reporting of cluster randomized trials.
authors: Medical Statistics Group, ScHARR, University of Sheffield, S1 4DA, UK.
authors: Michael J
authors: MJ
authors: Campbell
mesh_terms: D000465:Algorithms; D015982:Bias; D016000:Cluster Analysis; D003627:Data Interpretation, Statistical; D006801:Humans; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic / Q000941:ethics / Q000379:methods*; D012107:Research Design
keywords: cluster randomized trials; covariate adjustment; ethics; missing data; recruitment bias; sample size; stepped wedge