Survival, Cox Regression, Kaplan Meier, Weibull Distribution, Accelerated Failure Time.
assumption of a Cox-Regression is the Proportional Hazards Assumption (PHA). In SAS there are three methods to assess if this assumption has been breached: Creating Kaplan Meier plots for each categorical variable. Creating Schoenfeld residuals. Using the PROPHAZARD / PH option in PROC PHREG to