Balancing Efficiency and Fairness in Liver Transplant Access: Tradeoff Curves for the Assessment of Organ Distribution Policies.

Abstract

Current distribution policies have resulted in persistent geographic disparity in access to donated livers across the country for waitlisted candidates. Using mathematical optimization, and subsequently the Liver Simulation Allocation Model, the following organ distribution concepts were assessed: (1) current policy, (2) proposed alternative models, and (3) a novel continuous distribution model. A number of different scenarios for each policy distribution concept were generated and analyzed through efficiency-fairness tradeoff curves. The continuous distribution concept allowed both for the greatest reduction in patient deaths and for the most equitable geographic distribution across comparable organ transportation burden. When applied with an Optimized Prediction of Mortality allocation scheme, continuous distribution allowed for a significant reduction in number of deaths-on the order of 500 lives saved annually (https://livervis.github.io/). Tradeoff curves allow for a visualized understanding on the efficiency/fairness balance, and have demonstrated that liver candidates awaiting transplant would benefit from a model employing continuous distribution as this holds the greatest advantage for mortality reduction. Development and implementation of continuous distribution models for all solid organ transplants may allow for minimization of the geographic disparity in organ distribution, and allow for efficient and fair access to a limited national resource for all candidates.