PHREG Procedure

The PHREG procedure now fits frailty models with the addition of the RANDOM statement. You often use frailty models when you analyze clustered data and want to account for the within-cluster correlation with random effects. In addition, the NLOPTIONS statement is available with PROC PHREG, and the Zellner g-prior is now available for the piecewise exponential model.

The EFFECT statement is production.