Decreasing efficiency in deceased donor kidney offer notifications under the new distance-based kidney allocation system.

Organ Procurement Organizations (OPOs) recover deceased donor kidneys and place them with matched recipients according to ranked match runs of patients, but offer notification practices differ across the OPOs and have changed following updates to allocation policy (kidney allocation system 250 [KAS250]). This national registry study used batch notification data to quantify time spent on kidney allocation and identify variations in batch notification practices across OPOs before and after the KAS250 allocation system era. Overall allocation time between the first and last offer notifications increased from a median of 1 to 7 hours under the KAS250 allocation system. For match runs of unplaced kidneys, allocation time increased from a median of 18 to 28 hours. Out-of-sequence (OOS) allocation, used by OPOs to limit nonutilization due to excess cold ischemia time, more than doubled in frequency between 2018 and 2022, with median time from first offer to initiation of OOS varying across OPOs from 0 to 47 hours. Increasing rates of organ nonutilization and the observed allocation practice differences based on organ quality demonstrate the urgent need for new approaches to achieve more efficient placement of hard-to-place kidneys. Data-driven approaches to optimize kidney allocation efforts will help ensure fairness in a system that currently allows for wide practice variation and frequent OOS allocation.