Hi, My data set looks like: ID event Met_01 Start (days) Stop (days) Fu_time (stop-start) 1 0 0 0 230 230 1 1 1 230 1430 1200 2 1 0 0 907 907 3 0 0 0 365 365 3 1 1 365 790 425 When I am applying time varying Cox regression in SAS using following 2 codes then I am getting completely different Hazard Ratio (model 1: crude HR 0.95 and model 2:crude HR 0.74). Model 1: proc phreg data=test; class met_01/ref=first; model (start, stop) * event (0) = met_01/ties=EFRON RL; run; Model 2: proc phreg data=test; class met_01/ref=first; model fu_time* event (0) = met_01/ties=EFRON RL; run; I am not sure which one is to consider. Any help on this will be highly appreciated. I am struggling on this point from a long time.
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