PHREG Procedure

The CLASS statement, previously available only in the TPHREG procedure, is now included with the PHREG procedure. The BAYES statement provides Bayesian analysis via Gibbs sampling. PROC PHREG now fits the piecewise exponential model, which is specified in the BAYES statement. Bayesian baseline survival prediction becomes available with SAS 9.2 as well. The HAZARDRATIO statement provides a new facility for computing hazard ratios, including hazard ratios in the presence of interactions. The PLOTS option in the PROC PHREG statement produces baseline survival function plots. Profile-likelihood confidence limits are now available for hazard ratios produced in classical analyses. Firth’s penalized likelihood method is provided as well.