Racial Disparities in Pediatric Kidney Transplantation under the New Kidney Allocation System in the United States

Abstract

Background and objectivesIn December 2014, the Kidney Allocation System (KAS) was implemented to improve equity in access to transplantation, but preliminary studies in children show mixed results. Thus, we aimed to assess how the 2014 KAS policy change affected racial and ethnic disparities in pediatric kidney transplantation access and related outcomes.Design, setting, participants, & measurementsWe performed a retrospective cohort study of children <18 years of age active on the kidney transplant list from 2008 to 2019 using the Scientific Registry of Transplant Recipients. Log-logistic accelerated failure time models were used to determine the time from first activation on the transplant list and the time on dialysis to deceased donor transplant, each with KAS era or race and ethnicity as the exposure of interest. We used logistic regression to assess odds of delayed graft function. Log-rank tests assessed time to graft loss within racial and ethnic groups across KAS eras.ResultsAll children experienced longer wait times from activation to transplantation post-KAS. In univariable analysis, Black and Hispanic children and other children of color experienced longer times from activation to transplant compared with White children in both eras; this finding was largely attenuated after multivariable analysis (time ratio, 1.16; 95% confidence interval, 1.01 to 1.32; time ratio, 1.13; 95% confidence interval, 1.00 to 1.28; and time ratio, 1.17; 95% confidence interval, 0.96 to 1.41 post-KAS, respectively). Multivariable analysis also showed that racial and ethnic disparities in time from dialysis initiation to transplantation in the pre-KAS era were mitigated in the post-KAS era. There were no disparities in odds of delayed graft function. Black and Hispanic children experienced longer times with a functioning graft in the post-KAS era.ConclusionsNo racial and ethnic disparities from activation to deceased donor transplantation were seen before or after implementation of the KAS in multivariable analysis, whereas time on dialysis to transplantation and odds of short-term graft loss improved in equity after the implementation of the KAS, without compromising disparities in delayed graft function.PodcastThis article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_12_07_CJN06740521.mp3

The kidney allocation system and pediatric transplantation at 5 years

“…Black children continued to have the lowest transplant rates of all racial/ethnic groups. Conversely, Shelton et al reported an increase in transplant rate among Black pediatric candidates in the first 2 years after the introduction of KAS, 8 and Krissberg et al reported no change in waiting time 17 . Among adult candidates, Melanson et al reported an increase in transplant rate among Black and Hispanic adult candidates, but this increase was attenuated in more recent data 18 .…”

“…Racial disparities were another key target of KAS, although they were not as significant in pediatric candidates pre‐KAS; Krissberg et al report a time ratio for the time from activation to transplant among Black candidates that were 1.14 (95% CI 1.00–1.29) relative to Caucasian candidates 17 . However, our data did not show any increase in the transplant rate among Black and Hispanic candidates, even though transplant rates for Caucasian candidates increased significantly.…”

Pediatric Kidney Transplantation—Can We Do Better? The Promise and Limitations of Epitope/Eplet Matching

“…The 2014 Kidney Allocation System (KAS) deprioritized HLA matching and has narrowed the disparity in waitlist time among Black and Hispanic candidates and improved their transplant rates (72,73). Unfortunately, the same policy had the unintended consequence of prolonging pediatric waitlist times, highlighting the need for critical appraisal that policy change can have on clinical outcomes (74)(75)(76). Because organ allocation is an entangled dynamic system, in which change to one factor can significantly impact the others, prioritization of only one element often fails and highlights the pressing need to develop an allocation model that can optimize immunological matching but that can preserve pediatric priority, as well as minimize racial and geographic disparities (77,78).…”

Unrecognized opportunities: The landscape of pediatric kidney‐paired donation in the United States

“…Pediatric KT candidates and their families face increasingly complex choices under the kidney allocation system (KAS). [1][2][3] KAS policies aimed to improve longevity matching between donors and recipients and increase access for underserved populations. 4 While KAS successfully reduced deceased donor kidney transplant (DDKT) disparities between Black and White adult recipients (and some pediatric recipients), the overall rate of pediatric KT decreased.…”