Earlier, we introduced the concept of the semi-parametric model and the advantages of using PROC PHREG. Let's conduct a semi-parametric analysis on our survival data. We will use the stepwise methodology (selection option) to introduce the covariates in the model and give inclusion (slentry option) and exclusion criteria (slstay option) to control which covariate can enter the model and on what basis the covariate should be retained in the model. We also add an assess statement to test the proportional hazard (PH option) and linearity assumption (resample option) for the Cox regression model.
Here is the code for the PROC PHREG stepwise regression:
PROC PHREG Data=Survival_Analysis Plots=survival; Model ...
