The relationship of age, race, and ethnicity with survival in dialysis patients.

BACKGROUND AND OBJECTIVES: Reports on the racial and ethnic differences in dialysis patient survival rates have been inconsistent. The literature suggests that these survival differences may be modified by age as well as categorizing white race as inclusive of Hispanic ethnicity. The goal of this study was to better understand these associations by examining survival among US dialysis patients by age, ethnicity, and race.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Between 1995 and 2009, 1,282,201 incident dialysis patients ages 18 years or older were identified in the United States Renal Data System. Dialysis survival was compared among non-Hispanic blacks, non-Hispanic whites, and Hispanics overall and stratified by seven age groups.

RESULTS: The median duration of follow-up was 22.3 months. Compared with non-Hispanic whites, a lower mortality risk was seen in Hispanics in all age groups. Consequently, when Hispanic patients were excluded from the white race, the mortality rates in white race all increased. Using non-Hispanic whites as the reference, a significantly lower mortality risk for non-Hispanic blacks was consistently observed in all age groups above 30 years (unadjusted hazard ratios ranged from 0.70 to 0.87; all P<0.001). In the 18- to 30-years age group, there remained an increased mortality risk in blacks versus non-Hispanic whites after adjustment for case mix (adjusted hazard ratio=1.19, 95% confidence interval=1.13-1.25).

CONCLUSIONS: The mortality risk was lowest in Hispanics, intermediate in non-Hispanic blacks, and highest in non-Hispanic whites. This pattern generally holds in all age groups except for the 18- to 30-years group, where the adjusted mortality rate for non-Hispanic blacks exceeds the adjusted mortality rate of non-Hispanic whites.