Pediatric Age-Prioritized Waitlisting Policy Potentially Disadvantages Adolescents on Dialysis Not Listed for Transplant Until Adulthood.

Background: Current kidney transplant (KT) policies offer advantages in waiting time and organ allocation priority to pediatric patients waitlisted before 18 years old. This study evaluates the effects of this policy for patients who are on dialysis before, but not waitlisted until after, age 18.

Methods: Patients aged 11-25 years and waitlisted between 2001 and 2022 for KT were identified in the OPTN STAR data file for analysis. Cohorts were defined by age and dialysis status at time of listing: Peds if < 18 yo, young adult (YA) if ≥ 18 yo; NYOD-not yet on dialysis or OD-on dialysis at time of listing, with YA groups further segregated by age at dialysis initiation. Cumulative incidence of transplant was calculated for waitlisted patients. Graft survival was assessed using Kaplan-Meier analysis and multivariable Cox proportional hazards modeling. p values < 0.01 were significant.

Results: Amongst 35 764 KT registrations, candidates who initiated dialysis as pediatric patients but were not waitlisted until after turning 18 years old (YA + OD < 18) have the highest rate of nontransplantation (33.5%) and longest time on dialysis (median: 2103 days) before deceased donor (DD) KT. YA + OD < 18 patients were sixfold less likely than Peds + OD patients to undergo DDKT at 5 years after listing. YA + OD < 18 recipients had the worst post-KT graft survival of all groups at 5 years with adjusted hazard ratio of 1.477 (95% confidence interval: 1.218-1.792) compared to Peds-NYOD (p < 0.001).

Conclusions: Current allocation policies significantly disadvantage candidates who initiate dialysis before, but are not listed until after age 18, and should be re-examined to address these inequities.