The R package ClusROC This package implements the approaches for ROC surface analysis in the setting of clustered data. In particular, the following quantities are estimated: (i) the covariate-specific ROC surface; (ii) the covariate-specific volume under ROC surface (VUS); (iii) the covariate-specific optimal pairs of thresholds. The selection methods are: Generalized Youden Index (GYI), Closest to Perfection (CtP) and Max Volume (MV).