I am having trouble implementing the CLASS statement for categorical predictors (independent variables) in the PHREG procedure. If you've encountered this problem please share your solution if it has worked. Thanks!
This is an example from the SAS documentation website, although when I pasted this into the enhanced editor the "CLASS" statement remained red. This is the problem.
proc phreg data=VALung;
class Prior(ref='no') Cell(ref='large') Therapy(ref='standard');
model Time*Status(0) = Kps Duration Age Cell Prior|Therapy;