Persistent regional and racial disparities in nondirected living kidney donation.

Nondirected living donors (NDLDs) are an important and growing source of kidneys to help reduce the organ shortage. In its infancy, NDLD transplantation was clustered at a few transplant centers and rarely benefited African American (AA) recipients. However, NDLDs have increased 9.4-fold since 2000, and now are often used to initiate kidney paired donation chains. Therefore, we hypothesized that the initial geographic clustering and racial disparities may have improved. We used Scientific Registry of Transplant Recipients data to compare NDLDs and their recipients between 2008-2015 and 2000-2007. We found that NDLD increased an average of 12% per year, from 20 in 2000 to 188 in 2015 (IRR: 1.12, 95% CI: 1.11-1.13, P < .001). In 2000-2007, 18.3% of recipients of NDLD kidneys were AA; this decreased in 2008-2015 to 15.7%. NDLD transplants initially became more evenly distributed across centers (Gini 0.91 in 2000 to Gini 0.69 in 2011), but then became more clustered at fewer transplant centers (Gini 0.75 in 2015). Despite the increased number of NDLDs, racial disparities have worsened and the center-level distribution of NDLD transplants has narrowed in recent years.