Study Reveals Kidney Waitlisting Disparities, Inequitable Access to Transplantation

Syed Ali Husain, MD, MPH

Credit: Columbia University Irving Medical Center

Findings from a retrospective cohort study are calling attention to disparities in kidney transplant waitlisting based on sex, race, ethnicity, and employment status.

Among more than 50,000 patients aged ≤40 years with no major medical comorbidities, nearly half were not waitlisted for a kidney transplant within 5 years of dialysis initiation, with female sex, Black race, Hispanic ethnicity, and unemployment showing the greatest association with decreased waitlisting.¹

“Understanding the magnitude of underwaitlisting and waitlisting disparities is challenging due to difficulty determining the denominator of potentially waitlist-eligible patients,” wrote investigators.¹

End-stage kidney disease occurs when the kidneys have lost about 90% of their ability to function normally. In order to stay alive, patients need to have waste removed from their bloodstream through dialysis or a kidney transplant.² Patients who receive a kidney transplant typically live longer than those who stay on dialysis.³

To assess disparities in kidney transplant waitlisting, Syed Ali Husain, MD, MPH, assistant professor of medicine at Columbia University Medical Center, and a team of investigators used data from the US Renal Data System Registry to identify patients with end-stage kidney disease on dialysis and examined time to waitlisting for a kidney transplant. To be included in the study, patients were required to be ≥18 years of age and initiated dialysis between January 1, 2005, and December 31, 2019. Patients who were older than 40 years of age, received a preemptive transplant, were preemptively waitlisted, or had documented medical comorbidities other than hypertension or smoking were excluded.¹

In total, investigators enrolled 52,902 participants aged ≤40 years with no major medical comorbidities who initiated dialysis. Among the cohort, the mean age was 31 (standard deviation [SD], 5) years, 31,132 (59%) patients were male, 20,782 (39%) were Black/African American, and 28,006 (53%) were White.¹

Investigators categorized patients into 3 groups based on outcome: waitlisted after dialysis initiation but <1 year after dialysis initiation, waitlisted 1-5 years after dialysis initiation, or not waitlisted within 5 years of dialysis initiation. In total, 25,940 (49%) patients were not waitlisted by 5 years, while 11,122 (21%) were waitlisted between 1-5 years, and 15,840 (30%) patients were waitlisted within 1 year. The absolute differences in cumulative waitlisting at 1 and 5 years after dialysis initiation were −2% and −3% for female compared with male patients, −9% and −14% for Black patients compared with White patients, and −20% and −27% for unemployed patients compared with those who were employed full time.¹

In a model adjusted for age, sex, ethnicity, race, employment status, end-stage kidney disease Medicare coverage application, duration of prior nephrology care, and policy era, the following traits were associated with decreased waitlisting after dialysis initiation:

• Increased age (subhazard ratio [SHR], .98 per year; 95% confidence interval [CI], .97 to .98; P < .001)
• Female sex (SHR, .92; 95% CI, .90 to .94; P < .001)
• Hispanic ethnicity (SHR, .77; 95% CI, .75 to .80; P < .001)
• Black race (SHR, .66; 95% CI, .64 to .68; P < .001)
• Dialysis initiation after kidney allocation system (SHR, .75; 95% CI, .73 to .78; P < .001)

Of note, unemployment (SHR, .47; 95% CI, .45 to .48; P < .001) and part-time employment (SHR, .74; 95% CI, .70 to .77; P < .001) were associated with lower waitlisting compared to patients with full-time employment. More than 1 year of predialysis nephrology care, compared to none, was associated with greater waitlisting (SHR, 1.51; 95% CI, 1.46 to 1.56; P < .001).¹

“These findings in a population in which most patients should be medically suitable for transplant suggest that disparities in transplant waitlisting are not attributable to population differences in comorbidity burden but instead are likely reflective of structural racism in access to transplantation and that dialysis centers and transplant centers must be scrutinized on referral and waitlisting rates to ensure timely and equitable access to kidney transplantation,” investigators concluded.¹

References:

1. Husain SA, Yu ME, Ling KL, et al. Disparities in Kidney Transplant Waitlisting Among Young Patients Without Medical Comorbidities. JAMA Intern Med. doi:10.1001/jamainternmed.2023.5013
2. Mayo Clinic. Kidney transplant. Tests & Procedures. Accessed October 2, 2023. https://www.mayoclinic.org/tests-procedures/kidney-transplant/about/pac-20384777
3. Beth Israel Lahey Health. The Benefits of Kidney Transplant versus Dialysis. Kidney Transplant. Accessed October 2, 2023. https://www.bidmc.org/centers-and-departments/transplant-institute/kidney-transplant