A data frame with 50 rows and 2 columns: idx and
AE. AE lists the adverse event names in the statin49
dataset, while idx lists the cluster index of each adverse event.
The 49 AEs are classified into three clusters: 1) AEs associated with
signs and symptoms of muscle injury, 2) AEs associated with laboratory
tests for muscle injury, and 3) AEs associated with kidney injury and
its laboratory diagnosis and treatment.