Methods for sample size determination in cluster randomized trials.

ABSTRACT:

Background

The use of cluster randomized trials (CRTs) is increasing, along with the variety in their design and analysis. The simplest approach for their sample size calculation is to calculate the sample size assuming individual randomization and inflate this by a design effect to account for randomization by cluster. The assumptions of a simple design effect may not always be met; alternative or more complicated approaches are required.

Methods

We summarise a wide range of sample size methods available for cluster randomized trials. For those familiar with sample size calculations for individually randomized trials but with less experience in the clustered case, this manuscript provides formulae for a wide range of scenarios with associated explanation and recommendations

SUBMITTER: Rutterford C 

PROVIDER: S-EPMC4521133 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature