In Reply We appreciate the comments of Gentry et al in response to our published Viewpoint outlining the methodological shortcomings of the proposed “redistricting” model to solve geographic disparity in liver allocation.
In response to our critique that the model “has no mechanism to address geographic disparity occurring across districts,” Gentry et al respond that “[t]he proposed districts are designed with the primary goal of reducing disparities both within and between them.” Unfortunately, if this is true, this highlights a concerning lack of transparency. The published, deterministic optimization model that is used to determine the proposed solution includes numerous assumptions but no element for reducing disparity within a district. In fact, at the fundamental design level, the (re)districting solution is flawed in that it is incapable of responding to significant changes in organ demand across districts. We strongly believe, given the public funding of the Scientific Registry of Transplant Recipients (SRTR), that the entire model (the mathematical equations, not just select outputs) should be made publicly available in real time to allow for such an assertion to be externally tested and verified.
Ladner DP, Mehrotra S. Resolving Misconceptions About Liver Allocation and Redistricting Methodology—Reply. JAMA Surg. 2016;151(10):992. doi:10.1001/jamasurg.2016.1318