The simulated dataset includes 1500 rows, with each row represents information recorded from each individual.
There are 9 variables (columns). The treatment is the variable trt, which has two treatment arms. The clt is the cluster level.
The outcome of interest is variable Y. cov1-cov6 are pre-treatment covariates among which cov1-cov5 are continous, and cov6 is binary.