The presentation was given at the Joint Statistical Meetings 2005 in Minneapolis, MN. The presentation describes the use of standardized Kaplan-Meier estimation to compare survival across population subgroups when covariate adjustment is necessary and the proportional hazards assumption does not hold.

11. Weighting Example- Geographic Region Blacks: (60% South) Whites: (42% South) Study Population: (57% South) 7% 57% 60% 42%

12. Weighting Example (cont’) 36201 36201 Group Race Region Cases Weight Weighted Contribution 1 Black Northeast 7668 1.003 7691.004 2 Black South 17536 0.934 16378.624 3 Black North 2172 1.176 2554.272 4 Black West 1324 1.432 1895.968 5 White Northeast 2033 0.989 2010.637 6 White South 3117 1.373 4279.641 7 White North 1049 0.636 667.164 8 White West 1302 0.417 542.934 Total 36201

15. Standardized K-M Crude K-M d j = number of deaths at time t n j = number of persons at risk at time t W D (u)= sum of weights for cases who die at or before time t W R (u)= sum of weights for cases at risk at time t

16. Comparison of KM and SKM 12 months (95% CI) 24 months (95% CI) 36 months (95% CI) Whites SKM 0.927 (0.924, 0.929) 0.892 (0.889, 0.894) 0.868 (0.867, 0.870) KM 0.922 (0.916, 0.927) 0.884 (0.877, 0.891) 0.858 (0.850, 0.866) Hispanics SKM 0.927 (0.924, 0.930) 0.898 (0.896, 0.901) 0.871 (0.869, 0.873) KM 0.907 (0.901, 0.912) 0.872 (0.865, 0.878) 0.840 (0.832, 0.848) Blacks SKM 0.908 (0.906, 0.911) 0.863 (0.861, 0.866) 0.821 (0.819, 0.824) KM 0.907 (0.904, 0.910) 0.859 (0.855, 0.863) 0.815 (0.810, 0.819)