Equity, Utility, and Efficiency in Kidney Allocation: Understanding the Rise of Out-of-Sequence Allocation

Purpose of ReviewThe KAS250 policy introduced a broader kidney allocation radius, increasing system complexity and inefficiency, with kidney nonuse now approaching 30%. Simultaneously, new performance metrics have pressured organ procurement organizations (OPOs) to maximize utilization. In this landscape, out-of-sequence (OOS) allocation-bypassing the match run to expedite placement-has become more frequent. This review examines the rise of OOS allocation and its implications for equity, utility, and efficiency.Recent FindingsOriginally infrequent and intended for hard-to-place kidneys, OOS allocation now accounts for nearly 20% of transplants. Its use spans ranges of kidney quality and is concentrated among select OPOs and centers. The demographics of OOS recipients raise equity concerns regarding who benefits from access to OOS kidneys. It remains unclear if the practice of OOS allocation will help reduce kidney nonuse rates.SummaryThe rise of OOS allocation highlights the complexities of kidney allocation and challenges in balancing equity, utility, and efficiency. Without transparency and oversight, this practice risks worsening transplant disparities. Policy reforms are needed to ensure fair and effective kidney allocation.