Decreasing deceased donor transplant rates among children (≤6 years) under the new kidney allocation system

Abstract

The Kidney Allocation System (KAS) was implemented in December 2014 with unknown impact on the pediatric waitlist. To understand the effect of KAS on pediatric registrants, deceased donor kidney transplant (DDKT) rate was assessed using interrupted time series analysis and time-to-event analysis. Two allocation eras were defined with an intermediary washout period: Era 1 (01/01/2013-09/01/2014), Era 2 (09/01/2014-03/01/2015), and Era 3(03/01/2015-03/01/2017). When using Cox proportional hazards, there was no significant association between allocation era and DDKT likelihood as compared to Era 1 (Era 3: aHR: 1.07, 95% CI: 0.97-1.18, P = .17). However, this was not consistent across all subgroups. Specifically, while highly sensitized pediatric registrants were consistently less likely to be transplanted than their less sensitized counterparts, this disparity was attenuated in Era 3 (Era 1 aHR: 0.04, 95%CI: 0.01-0.14, P < .001; Era 3 aHR: 0.33, 95% CI: 0.21-0.53, P < .001) whereas the youngest registrants aged 0-6 experienced a 21% decrease in DDKT likelihood in Era 3 as compared to Era 1 (aHR: 0.79, 95% CI: 0.64-0.98, P = .03). Thus, while overall DDKT likelihood remained stable with the introduction of KAS, registrants ≤ 6 years of age were disadvantaged, warranting further study to ensure equitable access to transplantation.

Kidney transplant practice patterns and outcome benchmarks over 30 years: The 2018 report of the NAPRTCS

“…Higher HLA mismatch still confers a risk of worse allograft survival even in the post‐Share 35 era . Other publications have addressed the impact of these KAS criteria in allowing highly sensitized patients to receive a kidney transplant, and the temporary effect of diverting some DD kidneys from children <6 to the highly sensitized . To our knowledge, the effect of these policies in affecting recent late first AR rates has not been examined in detail.…”

Pediatric deceased donor kidney transplant outcomes under the Kidney Allocation System

“…Because prior studies have shown that younger recipients may have been uniquely disadvantaged by KAS, we also separately examined posttransplant outcomes among recipients <6 years old and <10 years old as a sensitivity analysis. 8,9 In addition, we performed a sensitivity analysis for the development of DGF including preemptive pDDKT recipients, as they composed almost 25% of our initial sample population.…”

“…Our finding of no statistically significant difference in DGF rates after KAS is in contrast to a study that reported a 69% increase in the odds of DGF for pDDKT recipients <10 years old. 8 This study included 5 years of pre-KAS recipients and 2 years of post-KAS recipients, focusing mainly on recipients <10 years old. In contrast, we limited our pre-KAS cohort to include only 2 years for all pDDKT recipients, to increase its comparability to our post-KAS cohort and limit the impact of any secular trends.…”

“…6,7 Nevertheless, a longer-term study showed that children <6 years old were 21% less likely to undergo DDKT after KAS implementation. 8 Moreover, a recent report showed that pDDKT recipients <10 years old experienced a 69% increase in the odds of delayed graft function (DGF) after KAS implementation, and recipients with DGF had a 2.2-fold increase in graft failure compared with those without DGF. 9 Finally, another study showed that the overall percentage of pDDKT recipients who received a pediatric donor kidney decreased post-KAS.…”

Changes in offer and acceptance patterns for pediatric kidney transplant candidates under the new Kidney Allocation System

“…One of these unintended changes has been a 21% decrease in deceased donor kidney transplant (DDKT) rates for candidates <6 years old. 4 Also, 2 studies have described a decrease in the number of pediatric recipients receiving organs from pediatric donors, with absolute decreases ranging from 3.3% to 11%. 5,6 Furthermore, 1 study noted a 121-day increase in the amount of time recipients <10 years old spent on the waitlist prior to transplant after KAS, and an absolute 6.7% increase in the percentage of recipients waiting longer than 1 year for transplant.…”