Increasing Discards as an Unintended Consequence of Recent Changes in United States Kidney Allocation Policy

Abstract

Kidney transplantation is the preferred treatment for end-stage kidney disease.1Wolfe RA Ashby VB Milford EL et al.Comparison of mortality in all patients on dialysis, patients on dialysis awaiting transplantation, and recipients of a first cadaveric transplant.N Engl J Med. 1999; 341: 1725-1730Crossref PubMed Scopus (3958) Google Scholar Despite a shortage of donated kidneys, the United States has the highest proportion of deceased donor kidneys (DDKs) recovered for transplant that are subsequently discarded, resulting in federal government prioritization of improving organ utilization.2Aubert O Reese PP Audry B et al.Disparities in Acceptance of Deceased Donor Kidneys Between the United States and France and Estimated Effects of Increased US Acceptance.JAMA Intern Med. 2019; 179: 1365-1374Crossref PubMed Scopus (83) Google Scholar,3ESRD Treatment Choices (ETC) Model. (Accessed 5 October 2022, at https://innovation.cms.gov/innovation-models/esrd-treatment-choices-model.)Google Scholar Simultaneously, there is increased emphasis on improving equity in transplant access, including a revised allocation system (“KAS250”) in March 2021 that removed strict geographic boundaries previously used in local organ allocation in an effort to reduce geographical heterogeneity in transplant rates.4Klarman SE Formica Jr., RN The Broader Sharing of Deceased Donor Kidneys Is an Ethical and Legal Imperative.J Am Soc Nephrol. 2020; 31: 1174-1176Crossref PubMed Scopus (0) Google Scholar However, KAS250 dramatically increased the complexity of interactions between transplant centers and organ procurement organizations (OPOs),5Adler JT Husain SA King KL Mohan S Greater complexity and monitoring of the new Kidney Allocation System: Implications and unintended consequences of concentric circle kidney allocation on network complexity.Am J Transplant. 2021; 21: 2007-2013Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar and the impacts of this change on organ utilization are not yet understood. Among these 96,834 DDKs recovered during the study period, 21,411 were discarded (22%), including 13,229/64,281 (21%) pre-KAS250 and 8,182/32,553 (25%) with KAS250 (p=0.004)— an increase that occurred despite similar overall quality of recovered DDKs in both eras (median Kidney Donor Profile Index [KDPI] 48% vs 51%). DDK discard has increased across all adult donor age groups (18-60 years: 16% vs 21%; ≥60 years: 54% vs 60%, Supplemental Figure S1), among DDKs with medium (18% vs 22%) and high KDPI (64% vs 68%; Figure 1A), and for DDKs from donors after both cardiac death (22% vs 31%) and brain death (20% vs 23%; Figure 1B). Discard of low KDPI DDKs was unchanged (3% vs 3%). An interrupted time series analysis also demonstrates an accelerated increase in DDK discards after the policy change (Supplemental Figure S2). DDK discard has also increased broadly among OPOs with high, medium, and low performance ratings (Figure 1C), indicating that this is not a geographic- or OPO-specific concern. The current discard rate for kidneys if present in prior years, after accounting for differences in discard rates for different quality organs, would result in 967 and 805 fewer transplants occurring in 2019 and 2020, respectively (Supplemental Table S1). Importantly, reasons for DDK discard also shifted with KAS250, with a greater proportion of discards attributable to exhaustion of the list of eligible candidates without organ acceptance (Figure 1D), supporting logistical complexity as a driver of worsened utilization. While the absolute number of DDK transplants has increased, over 1 in 4 DDKs recovered for transplant are not being transplanted, representing missed opportunities for hundreds of patients annually and increased healthcare system cost. This unintended deleterious consequence of the allocation system change requires urgent intervention to ensure that priceless organs are not wasted and that efforts to improve geographic equity in transplant do not come at a cost of worsening DDK utilization. SAH is supported by NIDDK grant K23 DK133729. Disclosures None Download .pdf (.27 MB) Help with pdf files