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

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.

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.

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.

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.