Characterizing Within-Center Placement of Out-of-Sequence Deceased-Donor Kidney Transplants

Deceased-donor kidney (DDK) allocation is intended to follow a ranked match-run of potential recipients. Organ procurement organizations (OPOs) can bypass this sequence and allocate kidneys "out-of-sequence" (OOS) to transplant centers, which then decide which of their candidates receives the kidney. We examine OOS placement practices within individual transplant centers.

We included the 5 US transplant centers that performed the most OOS kidney transplants from 2021 to 2023, representing 1598 OOS transplants. Candidates were classified as "skipped" if their transplant center declined an OOS kidney on their behalf and allocated the kidney to a patient lower on the center's waitlist. "Never-skipped" candidates received OOS kidney transplants without having been skipped. For each OOS transplant, we assessed how often the top-ranked candidate was skipped. We used mixed effects models to determine factors associated with being skipped.

Among included centers, the top candidate was skipped in 98% of OOS placements. The median OOS recipient within-center match-run rank was 23. Skipped candidates were younger (56 vs. 63 years) and had more dialysis exposure than never-skipped patients. Fewer than 50% of skipped candidates received a DDK transplant later in the study period (through 2023), and those who did received kidneys with a median Kidney Donor Profile Index (KDPI) 13 points higher than their lowest-KDPI skipped offer.

Younger candidates and those with longer dialysis durations were more likely to be skipped. A minority of skipped patients later received a lower KDPI (lower risk of graft failure) kidney. More transparency in OOS placement decisions is needed.