The extent and predictors of waiting time geographic disparity in kidney transplantation in the United States

Background: Waiting time to deceased donor kidney transplant varies greatly across the United States. This variation violates the final rule, a federal mandate, which demands geographic equity in organ allocation for transplantation. Methods: Retrospective analysis of the United States Renal Data System and United Network for Organ Sharing database from 2000 to 2009. Median waiting time was calculated for each of the 58 donor service areas (DSA) in the United States. Multivariate regression was performed to identify DSA predictors for long waiting times to kidney transplantation. Results: The median waiting time varied between the 58 DSAs from 0.61 to 4.57 years, ranging from 0.59 to 5.17 years for standard criteria donor kidneys and 0.41 to 4.69 years for expanded criteria donor kidneys. The disparity in waiting time between the DSAs grew from 3.26 years (range, 0.41-3.67) in 2000 to 4.72 years (range, 0.50-5.22) in 2009. In DSAs with longer waiting times, there were significantly more patients suffering from end-stage renal disease and more patients listed for kidney transplant, lower kidney procurement rates, and higher transplant center competition. Patients were more likely black, sensitized, with lower educational attainment and less likely to waitlist outside of their DSA of residence. Donor organs used in DSAs with long waiting times were more likely hepatitis C positive and had a higher kidney donor profile index. Graft and patient survival at 5 years was worse for deceased donor kidney transplant, but rates for living donor kidney transplant were higher. Conclusion: Our analysis demonstrates significant and worsening geographic disparity in waiting time for kidney transplant across the DSAs. Increase in living donor kidney transplant and use of marginal organs has not mitigated the disparity. Changes to the kidney allocation system might be required to resolve this extensive geographic disparity in kidney allocation.