While Cluster RCTs offer several advantages, they also come with unique challenges:
Intracluster Correlation: Individuals within the same cluster are likely to be more similar to each other than to individuals in other clusters. This intracluster correlation can reduce the statistical efficiency of the study. Sample Size Requirements: Due to the intracluster correlation, larger sample sizes are often required to achieve the same level of statistical power as individual randomized trials. Complex Analysis: The data analysis in Cluster RCTs is more complex and requires specialized statistical methods to account for the clustering effect.
