Efficient design of cluster randomized trials with treatment-dependent costs and treatment-dependent unknown variances.

ABSTRACT: Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, where treatment is randomly assigned to clusters. Current equations for the optimal sample size at the cluster and person level assume that the outcome variances and/or the study costs are known and homogeneous between treatment arms. This paper presents efficient yet robust designs for cluster randomized trials with treatment-dependent costs and treatment-dependent unknown variances, and compares these with 2 practical designs. First, the maximin design (MMD) is derived, which maximizes the minimum efficiency (minimizes the maximum sampling variance) of the treatment effect estimator over a range of treatment-to-control variance ratios. The MMD is then compared with the optimal design for homog

SUBMITTER: van Breukelen GJP 

PROVIDER: S-EPMC6120518 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature