Covariate Effects Via Cox Models
We have just seen evidence that the hazard for natural death is lower than that for the other two exit types, but that it increases more rapidly with time. On the other hand, the hazard functions for constitutional and nonconstitutional exits are nearly indistinguishable (despite the apparent differences in Output 6.2). We now look at whether the effects of covariates are the same or different across event types by fitting a Cox model to each type. The SAS program for doing this is as follows:
proc phreg data=leaders; model years*lost(0)=manner start military age conflict loginc growth pop land literacy / ties=efron; strata region; run; proc phreg data=leaders; model years*lost(0,1,2)=manner start military age ...
Get Survival Analysis Using SAS®: A Practical Guide now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.