PHREG Procedure
The PHREG procedure performs regression analysis of survival data based on the Cox proportional hazards model.
Cox's semiparametric model is widely used in the analysis of survival data to explain the effect of explanatory variables on hazard rates.
The following are highlights of the PHREG procedure's features:
 fits a superset of the Cox model, known as the multiplicative hazards model or the AndersonGill model
 fits frailty models
 fits competing risk model of Fine and Gray
 performs stratified analysis
 includes four methods for handling ties in the failure times
 provides four methods of variable selection
 permits an offset in the model
 performs weighted estimation
 enables you to use SAS programming statements within the procedure to modify values of the explanatory variables or to create ne explanatory variables
 tests linear hypotheses about the regression parameters
 estimates customized hazard ratios
 performs graphical and numerical assessment of the adequacy of the Cox regression model

 creates a new SAS data set that contains the baseline function estimates at the event times of each stratum for every specified set of covariates
 outputs survivor function estimates, residuals, and regression diagnostics
 performs conditional logistic regression analysis for matched casecontrol studies
 fits multinomial logit choice models for discrete choice data
 performs samplingbased Bayesian analysis
 performs BY group processing, which enables you to obtain separate analyses on grouped observations
 creates an output data set that contains parameter and covariance estimates
 creates an output data set that contains userspecified statistics
 creates a SAS data set that corresponds to any output table
 automatically created graphs by using ODS Graphics

For further details see the PHREG Procedure
Examples