Addressing Allocation Inefficiencies and Geographic Disparities

Friday, 14 February 2014
Columbus IJ (Hyatt Regency Chicago)
Sanjay Mehrotra , Northwestern University, Evanston, IL
Kidney transplantation (KT) is the most effective treatment for patients with end stage renal disease (ESRD).  In 2011, nearly 17,000 KTs were performed in the United States (US), but 94,000 patients remained on the KT waiting list.  This growing discrepancy between supply and demand has led to an increase in average waiting time for transplant from 3.3 years in 2000 to 4.72 years by 2009 to receive a KT after a patient is put on the waitlist wait.   As a direct consequence the cumulative time on dialysis and the mortality rate while awaiting a KT has increased.  Across the US, the disparity in waiting time while awaiting a transplant has increased from a median of 2.51 years in 1998 to 4.49 years by 2009.  This has significant implications on disparity in incurred cost and patient mortality across different regions of United States. 

The Department of Health and Human Services issued the “Final Rule” in 1998, which states, “Organs and tissues ought to be distributed on the basis of objective priority criteria and not on the basis of accidents of geography.”   Remarkably, despite this “Final Rule”, we find that the geographic disparity has worsened over time, not just in terms of waiting time, but other commonly accepted indicators as well.   This is in direct violation of the Final Rule.   The current United Network for Organ Sharing (UNOS) kidney allocation system allocates a procured kidney to the procuring DSA, prior to regional and national allocation.  Several strategies to reduce geographic disparities have been proposed and modeled.  A “variance” called Statewide Sharing, was granted by UNOS to Florida and Tennessee (TN) in the early 1990’s.   We found that waiting time as well as other indicators of geographic disparity dropped significantly since the granting of this variance.  In comparison the geographic disparity between the DSA in all the other states got worse between 1987 and 2009 or improved much less significantly.   Building on these findings, we present our overall strategy and framework for bringing a change to the issue of geographic waiting time disparity in kidney transplant.   We provide additional evidence for the viability of this strategy and estimated resulting improvements using extensive analysis using scientific tools from the areas of operations research, management science, mathematical simulation, and optimization.  Results show that significant improvement is possible in reducing waiting time disparity.  Additionally, when viewed from the national perspective, this will result in saving many lives.