PHREG: semi-parametric LIFETEST: non-parametric LIFEREG: parametric

1. PHREG: semi-parametricLIFETEST: non-parametricLIFEREG: parametric

2. Why can’t we use PROC LIFETEST to estimate baseline hazard increment?

3. LIFETEST does not accommodate left censoring

4. How to use PROC LIFETEST for dataset with left censoring?

5. Data set: subset of miners cohort data

6. *---- Non-Parametric using PHREG ----*; • procphregdata=uminers_rs; • model _rstime*_cc(0)= / entrytime=_rsentry rl; • baselineout=outcom cumhaz=cumhaz survival=sur/method=pl; • strata cr500; • run; • procprintdata=outcom; run;

8. *---- Non-Parametric using LIFETEST ----*; • odsoutput"Product-Limit Estimates"=ple; • proclifetestdata=uminers_rs method=pl; • id record; • time _setno*_cc(0); • strata cr500 _setno; • run; • odsoutputclose; • data ple2;set ple;where survival^=.;run; • *SAS output . for survival if there is no case;

10. PHREG: LIFETEST:

11. data ple2;set ple2; • retain survival0 survival1 1;retain cumhazard0 cumhazard1 0; • if cr500=0thendo • survival0=survival*survival0; sur=survival0; • cumhazard0=cumhazard0+failure; cumhazard=cumhazard0; • output; end; • if cr500=1thendo • survival1=survival*survival1; sur=survival1; • cumhazard1=cumhazard1+failure; cumhazard=cumhazard1; • output; end; • run;

12. PHREG: LIFETEST: (transformed)

13. Conclusion

14. Yes, we can use LIFETEST for datasets with left censoring.

15. But, PHREG is easier.

16. Thank you!