Generalized competing event model based on Cox PH model and Fine-Gray model.
This function is designed to develop optimized risk-stratification methods for competing
risks data, such as described in:
1. Carmona R, Gulaya S, Murphy JD, Rose BS, Wu J, Noticewala S,McHale MT, Yashar CM, Vaida F,
and Mell LK (2014)