Keeping Our Promise: Expedited Allocation for Prior Living Kidney Donors and Trends in Waiting Times According to...

Risks of kidney failure among prior living kidney donors (LKDs) are low, but an updated analysis of the impact of donor allocation priority on waiting times accounting for allocation changes and race has not been documented.

Using national UNOS data, we compared transplant rates, waiting time, and time on dialysis for prior LKDs with matched controls.  Waiting time was calculated based on initial registration and end waitlist date.

Transplant rate was 86.2 per 100 person years for LKD and 20.4 for matched controls (p < 0.001) corresponding to 83% of prior LKDs transplanted compared to 50% of matched controls (p < 0.001).  Median waiting time was 93 (27-371) days in the LKD group versus 692 (233-1351) days in the matched control group (p < 0.001). LKD waiting time pre- and post-implementation of the "new" Kidney Allocation System (KAS) was 133 (42-516) versus 67 (19-226) days, (p < 0.001). For LKDs, 56% were on dialysis prior to listing and 61% prior to transplant compared to 66% and 82% in controls, (both p < 0.001). Time on dialysis among LKDs post-KAS was comparable (pre-KAS: 547 (259-1352) versus post-KAS: 461 (231-942) days, p = 0.06). Waiting times were comparable according to race and ethnicity, but Black LKDs were more often on dialysis at the time of listing (Black 61% vs. white: 52%, p = 0.02), and time on dialysis was 36% (+155 days) longer in Black versus white LKDs (p = 0.0002).

LKD allocation priority results in a higher transplant rate and significant reduction in waiting time compared to matched controls, which improved post-KAS 2014.  Concerning, more than half of LKDs are on dialysis prior to listing and transplant with no substantial improvements in the post-KAS era.  Black LKDs experience lower transplant rates, 36% longer dialysis time compared to white LKDs, and are more likely to be on dialysis prior to listing and transplant.  Improved monitoring of LKDs and earlier transplant referrals are needed.