Survival Advantage of Black Dialysis Patients Limited to Older Adults

 

Compared to white patients, risk of death is lower for black dialysis patients over age 50 but higher for black patients in younger age groups, reports The Journal of the American Medical Association.

The researchers analyzed data on 1,330,007 patients with incident end-stage renal disease (ESRD) patients captured by the U.S. Renal Data System between 1995 and 2009. Multivariate age-stratified Cox proportional hazards and competing risk models were used to compare risk of death for black and white patients. Median potential follow-up was 6.7 years.

Overall mortality was lower in black patients than white patients: 57.1 percent versus 63.5 percent, adjusted hazard ratio (HR) 1.93. However, on age-stratified analysis treating kidney transplantation as a competing risk, mortality was higher for black patients in younger age groups. For those aged 18 to 30 years, mortality was 27.6 percent for black patients versus 14.2 percent for white patients: HR 1.93. This racial disparity remained significant from age 31 to 40 years, 37.4 percent versus 26.8 percent, HR 1.46; and from 41 to 50 years, 44.8 percent versus 38.0 percent, HR 1.12.

At age 51 to 60 years, the pattern reversed, with mortality of 50.9 percent for black patients and 51.5 percent for white patients: HR 0.93. This difference remained significant at older ages, with adjusted HRs of 0.87 from age 61 to 70, 0.85 from age 71 to 80, and 0.87 at age 80 and older.

Studies have consistently reported longer survival for black dialysis patients, compared to their white counterparts. The new study suggests that this survival advantage is limited to patients older than 50; in younger age groups, survival is lower for black patients than white patients. More study is needed to explore the reasons for the higher risk of death among young black patients on dialysis. [Kucirka LM, et al: Association of race and age with survival among patients undergoing dialysis. JAMA 2011; 171: 620–626].

December 2011 (Vol. 3, Number 12)