There are four SAS procedures for analyzing survival data:
The LIFEREG procedure is a parametric regression procedure for modeling the distribution of survival time with a set of concomitant variables.
The LIFETEST procedure is a nonparametric procedure for estimating the survivor function, comparing the underlying survival curves of two or more samples, and testing the association of survival time with other variables.
The PHREG procedure is a semiparametric procedure that fits the Cox proportional hazards model and its extensions.
The SURVEYPHREG procedure is a Cox modeling procedure similar to PROC PHREG, appropriate for data collected from a survey sample.