The Vexing Problem of Persistent Disparities in Kidney Transplant Care

Merriam-Webster defines the word vexing as, “causing or likely to cause vexation (a cause of trouble).” Persistent disparities in kidney transplantation care are a major vexation. Despite decades of intervention, Black Americans have been less likely to be referred for transplant, placed on the waitlist, or receive a transplant from a living donor as compared with White counterparts.^1–3 Other marginalized groups including racial and ethnic minorities, individuals with lower education, and those with fewer financial resources have also been less likely to be preemptively waitlisted.^1,2 These disparities demonstrate the overarching harm of compounding historical and current structural barriers influencing kidney health, including inequitable access to predialysis care, health care insurance, and essential health-promoting resources (e.g., housing, education, nutrition, and wealth).^1–3

Why do disparities in kidney transplant care persist? A robust body of literature has been devoted to elucidating multilevel barriers that occur at multiple junctures in the transplant journey and contribute to disparities in transplant receipt, including those occurring before kidney failure.^2–4 For instance, Black, Hispanic, and Asian individuals are less likely to receive predialysis nephrology care when compared with their White counterparts, and these disparities did not improve between 2005 and 2015.⁴ Minoritized individuals also experience unequal receipt of evidence-based disease-modifying therapies (e.g., sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 agonists⁵), suboptimal discussions about transplant options,⁶ and less referral for transplant evaluation. Early evidence suggested that the multimodal educational interventions about the 2014 kidney allocation system (KAS), which partly rectified transplant disparities resulting from late referral, could increase provider knowledge about KAS and disparities in transplant receipt for patients who are added to the waitlist.^6,7 Yet, the impact of this type of intervention on disparities in rates of waitlist placement was previously unknown.

In this issue of CJASN, Patzer, et al.⁸ present findings from The Allocation System Changes for Equity in Kidney Transplantation (ASCENT), a cluster-randomized pragmatic effectiveness-implementation trial designed to increase kidney transplant waitlisting and reduce racial disparities in waitlisting across US dialysis facilities. ASCENT investigators randomized 655 US dialysis facilities in the lowest tertile of kidney transplantation waitlisting rates to receive a multilevel, multimodal educational intervention including performance feedback reporting versus control and subsequently assessed a primary outcome of changes in facility waitlisting percentages and racial differences in waitlisting at 1 year postintervention, for both incident and prevalent patients with kidney failure. This intervention directly responded to findings that at baseline, overall knowledge of racial disparities in waitlisting and KAS was low (19% overall) among dialysis staff.⁷ Among an estimated 56,332 prevalent and 23,623 incident dialysis patients, investigators identified low transplant waitlist rates overall and substantial racial disparities in waitlisting at baseline among incident patients. Although the ASCENT intervention did not yield significant overall increases in waitlisting rates, Black-White patient disparities in waitlisting were attenuated. The intervention also improved absolute waitlisting among Black patients in the intervention group, with 0.87% waitlisted at baseline versus 1.07% at follow-up (difference-in-difference of percentages 0.17%, 95% confidence interval [CI], 0.06% to 0.28%). Notably, ASCENT investigators also corroborate the persistence of stark racial disparities in transplant waitlisting between Black and White individuals with incident kidney failure, whereby Black individuals had lower odds of waitlisting versus White counterparts (odds ratio [OR], 0.67; 95% CI, 0.48% to 0.94%) at baseline. Among incident patients, there were no significant differences in waitlisting among intervention versus controls recipients at 1 year (OR, 0.94; 95% CI, 0.63% to 1.39%). However, Black-White patient disparities were significantly attenuated in the intervention group (adjusted odds shifted from 0.56; 95% CI, 0.35% to 0.92% to 0.84%; 95% CI, 0.49% to 1.42%) versus the control group. Despite the comprehensive educational intervention, increased intervention group knowledge and behaviors did not statistically significantly improve.

Persistent waitlisting disparities among patients with incident kidney failure remain alarming. Why is it so difficult to eliminate these disparities? Through their novel study, Patzer and colleagues corroborate multidecade findings of stark racial inequities in kidney transplant care, particularly among incident dialysis patients, as well as recent findings of declines in overall waitlisting post-KAS and improved racial equity in waitlisting among prevalent patients. In addition, study authors noted that among included facilities falling within the lowest quartile of waitlisting performance, most (69%) were in the Southern US Census region, and nearly half (43%) were within the highest two quintiles of high poverty areas. Further study is needed to better understand the influence of neighborhood-level barriers, such as poverty and other geographical factors (e.g., disinvestment and resource deprivation that predominantly burdens minoritized communities who were historically redlined because of racist US housing policies), on the success of interventions to tackle disparities in kidney transplant care.

Limitations of this study and available data also warrant attention. First, it is difficult to discern which specific steps before transplant waitlisting (e.g., discussions with patients, education, referral, and the complex multilevel process of transplant evaluation) were blockades to waitlisting in this study. Lack of transparent national data describing process measures pre-requisite for successful kidney transplant waitlisting including dialysis unit referrals further impedes identification of units that could benefit from targeted interventions. For instance, provision of tailored multilevel resources (e.g., transportation, education, navigation of barriers, financial support) for patients facing the greatest challenges within certain regions (e.g., regions that did not experience Medicaid expansion) and dialysis units may be essential to reduce disparities. Additional data are also essential to understanding and rectifying any inclination by dialysis units to prescreen for transplant candidacy and thus preferentially refer based on preconceived criteria. More transparency is also needed for transplant center–level data, including time to evaluation initiation and transplant receipt. This may help identify and provide targeted support to centers experiencing challenges, including high referral volume. Finally, additional information regarding transplant center time to evaluation completion and reasons for immediate refusal of a potential candidate may improve clarity and consistency for transplant evaluation metrics, thereby mitigating potential biases that impede the evaluation process.

For instance, identification of adherence concerns by providers should prompt further evaluation of the structural barriers that impede adherence, which transplant and dialysis centers could leverage to better support patients and caregivers (e.g., food insecurity, transportation) to overcome these barriers. In addition, several nonstandardized evaluation criteria including assessments of social support may disproportionately harm individuals who may be more likely to have competing demands that impede being present for all evaluation visits, including childcare, work, and transportation concerns. Identifying barriers that delay evaluation completion (e.g., colonoscopy, mammography screening) should also be identified and reported with clear pathways for patients to be supported to overcome these. The low prevalence of potential comorbid medical contraindications to transplant (e.g., mean prevalence of 6.8% cancer, 10.2% chronic obstructive pulmonary disorder) in this low-waitlisting cohort warrants further investigation into multilevel contributors to overall low waitlisting rates.

Key findings from the ASCENT study also provide some insights regarding several potential intervention targets, such as timely high-quality pretransplant nephrology care, effective transplant education, and early support for candidates to identify and address clinical and nonclinical barriers to transplant. Centers for Medicare & Medicaid Services performance metrics focusing exclusively on dialysis facility kidney transplant waitlisting rates may also miss important opportunities to incentivize earlier intervention in the transplant journey (e.g., dialysis unit referral, ensuring predialysis care includes high-quality kidney transplant education and resources). These study findings must also be considered in the context of other national data suggesting disparities have grown post-KAS in preemptive kidney transplantation and living donor kidney transplant, which confer optimal graft and patient outcomes. For instance, in a study of preemptive transplantation before and after KAS, non-White race, younger age, male sex, lower educational attainment, and public primary insurance were associated with lower odds of preemptive transplant after KAS.⁹ Most egregious, living donor kidney transplant disparities have grown over the last decade such that Black individuals were found to have 73% lower access to transplantation compared with White individuals in a landmark study.³

“Speak up, speak out, get in the way. Get in good trouble, necessary trouble, and help redeem the soul of America.”—US Representative and Civil Rights Leader John Lewis.

What will it take for us to tackle the vexing problem of disparities in kidney transplant care? Overall, the findings by Patzer et al. represent another call to action for the US kidney care community. Multimodal education and feedback designed to optimize implementation of policy reform, such as KAS, are necessary components of equity-focused transplant reform. Previously, policy interventions, including Medicaid expansion, contributed to larger increases in Medicaid coverage among racial and ethnic minority preemptive transplant listings than White patients' transplant listings post-KAS.¹⁰ Initiatives that fundamentally improve resource equity through health insurance provision may be essential to couple with transplant-specific policy interventions. Yet, singular efforts such as education or policy reform alone will not achieve transplant equity. Successful interventions will require concerted investment in enhancing transparency and addressing the multilevel structural barriers to kidney transplant, including inequitable predialysis health care and resource gaps that exacerbate the challenges of a complex referral and evaluation process. These coordinated efforts must include promotion of broad structural reforms including expanded access to high-quality health care and insurance coverage required for optimal pretransplant care including management of comorbidities, as well as coordinated efforts to mitigate the structural barriers throughout evaluation, including physical access to and coverage to complete required testing. More work is also needed to understand the influence of regional, policy, and sociocontextual contributions on interventions to redress transplant disparities. As we strive to eradicate the persistent disparities of the present, we must center patient, family, and community input in our solutions. Through multilevel investment to remove structural barriers and enhance transparency and collaboration, we can achieve the goals set forth in the National Academies of Medicine 2022 report, “Realizing the Promise of Equity in the Organ Transplantation System.” Importantly, the achievement of equity in transplantation will require all professionals involved in the spectrum of transplant care (ranging from primary care providers, to nephrologists, to transplant center professionals, as well as patient and community advocates) to prioritize addressing long-standing barriers to kidney transplantation.

Disclosures

D. Mohottige reports honoraria from MedScape (CME); advisory or leadership roles for ESRD National Coordinating Center Health Equity Advisory Committee, Healio Editorial advisory board, NKF Health Equity Taskforce, and NKF Transplant Advisory Committee—all nonpaid; and other interests or relationships as ESRD NCC Equity Taskforce Member, NIH SDOH PHENX Workgroup, NKF Health Equity Advisory Committee member, and NKF Transplant Advisory Committee Member. T.S. Purnell is Co-Lead of the Education Workgroup for the American Society of Nephrology (ASN) Health Care Justice Committee; a member of the NKF Transplant Advisory Committee; and a member of the Governing Board of Directors for both the Living Legacy Foundation of Maryland and the National Minority Organ Tissue Transplant Education Program (MOTTEP)—all nonpaid.

Funding

D. Mohottige was supported by the National Kidney Foundation (NKF) Young Investigator Award. T.S. Purnell was supported by grant K01HS024600 from the Agency for Healthcare Research and Quality (AHRQ).

Author Contributions

All authors conceptualized the study, wrote the original draft, and reviewed and edited the manuscript.