A simulated data set for ODACH with case-cohort design demonstration
odach_ccA data frame with 413 rows and 8 variables:
site id, 187 'site1', 133 'site2', 93 'site3'. The full_cohort_size are 800, 600 and 400 respectively
1=subcohort, e.g. uniformly subsampled from full_cohort_size, 0=case
survival time
censoring status 0=censored, 1=dead
the first covariate, continuous
the second covariate, continuous
the third covariate, categorical
the fourth covariate, categorical