Transplantation discrepancies between Black and white patients have been found to contribute significantly to differing survival rates for childhood-onset kidney failure across the two racial groups.
Reporting these findings in the Journal of the American Society of Nephrology (JASN), Ivonne Schulman, Susan Mendley (National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, USA) and colleagues also conclude that equalising time with a functioning transplant for Black patients may help to equalise their survival rates from childhood-onset end-stage kidney disease as compared to white counterparts.
Schulman, Mendley and their co-authors begin by noting that this phenomenon—the role played by kidney transplantation in differential survival for Black and white patients with childhood-onset kidney failure—is currently “unexplored”.
As such, they analysed 30-year cohort data from children beginning renal replacement therapy before the age of 18 years between January 1980 and December 2017 in the US Renal Data System. Schulman, Mendley and colleagues’ analysis identified a total of 28,337 patients within these criteria.
In their JASN report, they detail that Cox regression identified transplant factors associated with survival by race, while the survival mediational g-formula was used to estimate the excess mortality among Black patients that could be eliminated if an intervention equalised their time with a transplant to that of white patients.
Black children comprised 24% of the cohort and their crude 30-year survival was 39% compared to 57% for white children (p<0.001), according to Schulman, Mendley and colleagues’ findings. In addition, Black children had a 45% higher risk of death (adjusted hazard ratio [aHR]=1.45; 95% confidence interval [CI]=1.36, 1.54), and a 31% lower incidence of first transplant (aHR=0.69; 95% CI=0.67, 0.72) and a 39% lower incidence of second transplant (aHR=0.61; CI=0.57, 0.65).
The authors further detail that children and young adults are likely to require multiple transplants—yet, even after their first transplant, Black patients had 11% fewer total transplants (adjusted incidence rate ratio [aIRR]=0.89; 95% CI=0.86, 0.92). In Black patients, kidney grafts also failed earlier after both first and second transplants, with Black patients spending 24% less of their renal replacement therapy time with a transplant when compared to their white counterparts (aIRR=0.76; 95% CI=0.74, 0.78).
Lastly, Schulman, Mendley and colleagues state that transplantation compared with dialysis strongly protected against death (aHR=0.28; 95% CI=0.16, 0.48), as per time-varying analysis, and mediation analyses estimated that equalising transplant duration could prevent 35% (p<0.001) of excess deaths in Black patients.