Association between out-of-sequence allocation and deceased donor kidney nonuse across organ procurement organizations.

Out-of-sequence (OOS) kidney allocation has become increasingly prevalent since 2021. We examined the relationship between organ procurement organization (OPO) OOS allocation frequency and kidney nonuse rates. Among 57 OPOs between March 2021 and December 2023, we analyzed trends in OOS utilization and its association with kidney nonuse rates. There was significant variability in OOS use across OPOs, with some allocating over 20% of kidneys out-of-sequence over the entire period. An absolute increase of 1 SD (12.8%) of OOS allocation was modestly associated with a reduction in kidney nonuse rates (incidence risk ratio = 0.98; P = .04). Donor characteristics, particularly older age, donation after circulatory death, and high kidney donor profile index, were the strongest predictors of nonuse. While OOS allocation may mitigate logistical challenges, other strategies may be more effective at reducing the nonuse rate.