What is the difference between: 1- Augemented IPW with proc causaltreat statment  2- Doing multivariable cox regression with proc phreg with Adding a weight statment with IPW weight? proc phreg data=***; weight ipw; model Time_to_event*mortality(0)= variable1 variable2 ...... / rl; run;     I prefer the second one because it takes into account time to event analysis, while the first way seems to not be taking into account time to event.    Any advice? thanks ... View more