Decreased graft loss following implementation of the kidney allocation score (KAS)

Background: The Kidney Allocation System (KAS) was developed to improve equity and utility in organ allocation. We examine the effect of this change on kidney graft distribution and survival. Methods: UNOS data was used to identify first-time adult recipients of a deceased donor kidney-alone transplant pre-KAS (Jan 2012–Dec 2014, n = 26,612) and post-KAS (Jan 2015–Dec 2017, n = 30,701), as well as grafts recovered Jan 2012–Jun 2019. Results: Post-KAS, kidneys were more likely to experience cold ischemia time >24 h (20.0% vs. 18.8%, p < 0.001) and experienced more delayed graft function, though competing risks modeling demonstrated a lower hazard of graft loss post-KAS, HR 0.90 (95% CI 0.84–0.97, p = 0.007). Post-policy, KDPI >85% kidneys were more likely to be shared regionally (37% vs. 14%), and more likely to be discarded (60.6% vs. 54.9%) after the policy change. KDPI >85% graft and patient survival did not change. Conclusions: Implementation of the KAS has increased sharing of high-KDPI kidneys and has decreased the hazard of graft loss without an impact on patient survival.