By Crystal Phend
Young black patients don’t survive as long on dialysis as their white counterparts, according to a national study that challenges notions of a black advantage for dialysis.
As seen in many prior studies, the overall mortality on dialysis came in lower for black than for white patients at 57.1 percent versus 63.5 percent (P<0.001), Dorry L. Segev, MD, PhD, of Johns Hopkins, and colleagues found.
However, black 18- to 30-year olds were nearly twice as likely to die on dialysis as white patients of the same age (27.6 percent versus 14.2 percent, adjusted hazard ratio 1.93, P<0.001).
That higher risk for black patients remained through age 50, after which the trend switched to a survival advantage, the researchers reported in the August issue of the Journal of the American Medical Association.
Younger patients may fundamentally differ in comorbidities, underlying disease biology, and socioeconomic status — all factors that influence outcomes, the researchers noted.
Even the survival advantage for blacks on dialysis overall is a conundrum, although replicated in study after study, they pointed out.
Racial disparities in quality of care and access to it have been well documented, with black patients less likely to receive an adequate dialysis dose or a fistula, achieve target hemoglobin levels, or receive kidney transplantation.
Worse, the perception of better survival on dialysis for black patients “seems to have affected clinical decision making and engendered complacency about the low rates of transplantation among black patients,” Segev and colleagues wrote.
Since Medicare may blunt some of the disparities in care for seniors — who dominate the dialysis ranks — Segev’s group stratified by age in analyzing the United States Renal Data System.
This national registry of all end-stage renal disease patients included 407,140 patients who identified themselves a black or African American and 922,867 who identified as white or Caucasian on CMS forms.
Black patients in the registry were less likely to get kidney transplants (9.1 percent versus 12.4 percent of white patients overall), particularly in the youngest, 18-to-30 age group (31.9 percent versus 54.9 percent).
The researchers dug into potential explanations for the disparity in survival for the 18- to 30-year-olds, which was greater than that in any other age group.
They found that black 18- to 30-year-olds on dialysis were:
- Less likely to have private insurance
- More likely to have Medicaid or no insurance
- More likely to have hypertension as primary cause of renal failure
- Less likely to receive erythropoietin, “a proxy for medical care during chronic kidney disease progression”
The researchers cautioned that their analysis included only patients who survived long enough to develop end-stage renal disease and didn’t include details on comorbidities, such as severity.
“Black patients with chronic kidney disease die at a higher rate than their white counterparts, possibly causing a survivor bias in which the black patients who survive to end-stage renal disease are healthier than white patients who survive to end-stage renal disease,” they wrote in the paper.
The study was supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases and by an award cofunded by the National Institute on Aging and the American Federation for Aging Research.