Working on a Cox Proportional Hazard model and have a question about dummy categories and censoring. Much like regular regressions, do you need to drop one of the dummy categories?
In terms of censoring, I am analyzing the effect on mortality rates. So my time dimension will be duration between surey and date of death (in years). I called this term 'survival'
The right censoring variable is death status, alive or dead. Where dead = 1 and alive = 0. This term was labeled 'mortality'
So the equation I have come up with is:
proc phreg data = test;
model survival*mortality(0) = sex age_cat_1 age_cat_2 smoking_status ...
/ rl ties=efron ;
run;
Any thoughts as to whether the censoring looks right and what to do about dummy variables would be greatly appreciated.