The effects of DonorNet 2007 on kidney distribution equity and efficiency

In 2007, UNOS released DonorNet 2007 (DN07) in hope of improving allocation equity and efficiency. We hypothesized that hard-to-place organs might be less efficiently handled through this regimented process. We analyzed associations between DN07 and center-level equity, number of refusals per organ and cold ischemia time (CIT). A total of 8244 kidney transplants between 1/2006 and 12/2006 (pre-DN07) were compared with 6029 transplants between 5/2007 and 2/2008 (post-DN07). Distribution equity was assessed by the Gini coefficient, changes in the number of refusals and CIT by negative binomial regression and discard rates by logistic regression. We estimated quantile-specific differences in CIT by bootstrapping. We found no significant change in center-level distribution equity after DN07. Number of refusals per organ increased by 20% (adjusted rate ratio (1.12)1.20(1.28), p < 0.001) at the patient level and 11% (ARR (1.07)1.11(1.16), p < 0.001) at the center level. Regression models of CIT showed no global change in CIT associated with DN07, but those kidneys with the longest CIT pre-DN07 had statistically significantly longer CIT post-DN07. The discard rate also increased significantly (ARR (1.06)1.11(1.17), p < 0.001). DN07 has not improved equity or efficiency in allocation of deceased donor kidneys, and may be harming the allocation of hard-to-place kidneys.