A simulation study of cadaveric liver allocation with a single-score patient prioritization formula

In this article, we present a simulation study on prioritizing patients for receiving scarce cadaveric liver donations. We propose a ranking formula that combines the four criteria commonly used for prioritizing wait-list liver transplant candidates. We apply the proposed ranking formula to evaluate several system outcomes in a liver-allocation simulation model. For each outcome, we identify promising schemes that outperform the currently implemented scheme by analysing the response surfaces constructed with a mixture design of simulation experiments on the four criteria. We also show that it is unlikely to have a scheme that reduces pretransplant mortality and improves other system outcomes simultaneously. Finally, we conduct sensitivity analyses on the two subjective scalars in the ranking formula. Overall, our simulation study shows that the proposed ranking formula and the mixture design approach allow us to systematically analyse patient prioritization in liver transplantation and allocation.