Cluster Rct Power Calculation. Thus the unit of randomization may be different from the unit of analysis. A motivating example from a malaria vector control trial International Journal of Epidemiology Volume 49 Issue 3 June 2020 Pages 954962.
The help file is useful and you can install a dialog box for it by following the instructions at the end of the help file. In other situations cluster randomization at the unit or hospital floor level is being considered so the sample size estimates are a little more involved. Jul 14 2017 The exact calculations are shown in Appendix 1.
Nov 01 2012 SE of the treatment effect in a cluster randomized trial as a function of the cluster size n and ICC ρ under the budget constraint B K c sn where B budget K number of clusters c cost per cluster and s cost per person outcome variance σ y 2 100 B 10000 c 300 and s 10.
A key property of cluster randomization trials is that inferences are frequently intended to apply at the individual level while randomization is at the cluster or group level. Jun 30 2011 For a CRCT with a fixed number of clusters k per arm with a fixed number of individuals per cluster m and with power 1 - β then the detectable difference d C follows straightforwardly from equation 1. 365 members per cluster has more than 95 power whereas for that same ICC and same total sample size 11700 now divided equally between a total of 20 clusters ie. Thus the unit of randomization may be different from the unit of analysis.
