A study in the August 10 issue of JAMA reveals, that despite the fact that overall black patients have a lower risk of death during dialysis than white patients, this seems to apply primarily to older adults; black patients age 50 years or younger have a significantly higher risk of death.
According to background information in the article,
“Of more than 500,000 individuals with end-stage renal disease (ESRD) in the United States, approximately one-third are black, and the relative incidence of ESRD is 3.6 times higher among black than white patients. Moreover, racial disparities in quality of and access to care for patients with kidney disease are well-documented. Compared with white patients, fewer black patients with chronic kidney disease (CKD) are under the care of a nephrologist, and their rates of referral for peritoneal dialysis and kidney transplantation are significantly lower.”
In addition, black patients receiving dialysis are less likely to receive an adequate dialysis dose and achieve target hemoglobin levels (metrics associated with decreased dialysis survival).
The authors write,
“Despite the disparity in care, current thinking, supported by more than 30 previous studies, is that black patients receiving dialysis survive longer than their white counterparts. This observation is paradoxical given racial disparities in access to and quality of care, and is inconsistent with observed lower survival among black patients with chronic kidney disease.”
Research lead by Lauren M. Kucirka, Sc.M., of the Johns Hopkins University School of Medicine, Baltimore, and fellow colleagues examined, whether age could be an effect modifier of the racial differences observed in dialysis survival, and if differential rates of kidney transplantation modify the risk of death in dialysis patients. Data for the study was collated from the United States Renal Data System from January 1995 until September 2009 with an average (midpoint) potential follow-up time of 6.7 years, comprising of 1,330,007 incident end-stage renal disease patients.
Data analysis suggests that overall, black patients had a lower death rate during analysis compared to white patients. The death toll of new ESRD patients for dialysis recipients was 57.1 percent of black and 63.5 percent irrespective of age during the study. 9.1 percent of black and 12.4 percent of white patients received kidney transplants of which 25.7 percent of transplants in black patients were provided from live donors compared to 42.8 percent in white patients. The investigators discovered however, that the relationship between race, dialysis survival, and transplantation changed considerably with patient age, with opposite implications in the younger age groups.
When the results were differentiated by age and treating kidney transplantation as a competing risk, it turned out, that black patients had a significantly higher death rate than their white counterparts between the ages of 18 to 50 years with almost double the risk of death for those aged between 18 and 30 years, compared with patients aged 51 years or older.
The authors write,
“… the demonstration of significant age-based effect modification of the racial differences in dialysis survival is novel, challenging conventional wisdom and identifying a significant disparity among younger black patients that needs to be addressed.”
The methods utilized in this study allows the authors to reason,
“the 2-fold increased hazard of death on dialysis in younger black patients is composed of 2 distinct components: one of differential rates of transplantation and one of biology (or some interaction between biology and socioeconomic factors). Blacks are much less likely to receive a transplant from a live donor; as such interventions to reduce transplant disparities should prioritize the improvement of live donation rates for blacks.”
The authors conclude,
“Determining why younger black patients are at increased risk of death as dialysis recipients is critical in order to improve clinical decision making and inform policies aimed at achieving equity in ESRD care.”
Written by Petra Rattue