Among patients with kidney failure, the largest disparities in the use of kidney transplant and home dialysis are among younger Black and Hispanic patients, according to Adam S. Wilk, PhD.

For an observational study published in the American Journal of Kidney Diseases, Dr. Wilk and colleagues compared the use of kidney replacement therapies between racial and ethnic groups by age and incident kidney failure overall.

They conducted a retrospective cohort study of more than 830,000 United States adults who initiated kidney failure treatment between 2011- 2018. Of these patients, 52% were non-Hispanic White, 26% were non-Hispanic Black, and 15% were Hispanic, with other racial/ethnic groups making up the remainder. Across racial/ethnic groups, 3% of patients received a transplant by day 90 of treatment, while 81% used in-center hemodialysis (ICHD), 10.5% used peritoneal dialysis (PD), 0.7% used home hemodialysis (HHD), and 1.2% used other treatment modalities, whereas 4% were not assigned to any treatment because they were not on any treatment for more than 60 days (Figure).

Disparities Widest Among Patients Aged 22-44 at Treatment Initiation

“Black and Hispanic patients were significantly less likely than non-Hispanic White patients to undergo transplant or HHD treatment within 90 days of initiating kidney replacement treatment, which was not surprising, as it was consistent with prior studies,” Dr. Wilk says. “However, it was notable that these disparities were widest among patients aged 22-44 at the time of initiating treatment.”

These findings, he explains, are contrary to what one should expect since kidney failure in Black and Hispanic individuals usually occurs at earlier ages, and transplants and HHD are more commonly used by younger versus older patients in clinical practice. “We were concerned that there was an important relationship between patient age and racial and ethnic disparities in treatment use that was not well understood,” he says.

Greatest Disparity for Transplant Observed Among Black Patients

When examining treatments used in each racial/ ethnic group, disparities were most pronounced in Black patients aged 22-44 at treatment initiation. Among White patients in this age group, 10.9% were treated with transplant, 19% with PD, and 1.2% with HHD. These percentages were significantly lower for Black patients at 1.8%, 13.8%, and 0.6%, respectively, and Hispanic patients at 4.4%, 16.9%, and 0.5%, respectively.

After adjusting for the probabilities of transplant, PD, and HHD by age across racial/ethnic groups, the largest relative disparities were observed for transplant. Although disparities were found across all Black and Hispanic age groups versus their White counterparts, the greatest disparity for transplant was observed among Black patients. Compared with White patients, Black patients aged 22-44 had an adjusted risk ratio (aRR) of 0.21 (95% CI, 0.19 0.23). Disparities among Black patients in other age groups were also large, with aRRs ranging from 0.29-0.30. Similarly, the greatest disparity in transplant for Hispanic patients was among those aged 22-44, with an aRR of 0.47 (95% CI, 0.43-0.51), but only marginally smaller in older age groups, with aRRs ranging from 0.49-0.50.

Account for Age When Treating Kidney Failure

When considering disparities in HHD use, similar patterns for transplant emerged, with young Hispanic and Black patients showing the largest disparities relative to nonHispanic White patients. Among those aged 22-44, the aRR for Hispanic patients was 0.34 (95% CI, 0.27-0.43) and the aRR for Black patients was 0.45 (95% CI, 0.38-0.54). These disparities were significantly smaller or eliminated among older cohorts in both populations. In contrast, disparities in PD use for Black and Hispanic patients was larger among older age groups than for younger age groups.

“If we don’t account for differences in age at the time of initiating treatment, our estimates of the magnitude of these disparities overall are too small,” Dr. Wilk says. “We must account for age to see the actual, very large size of these disparities when considering how they might affect a typical patient, particularly a younger patient.”

Dr Wilk advocates for programs and interventions to improve equity in the treatment of Black and Hispanic adults with incident kidney failure, noting these programs “may have the greatest potential when focused on the needs and barriers faced by younger individuals— those who stand to gain the most in accumulated life expectancy and QOL when receiving a preferred kidney failure treatment.”