Impact of the Model for End-Stage Liver Disease Allocation Policy on the Use of High-Risk Organs for Liver Transplantation

Abstract

Although priority for liver transplantation is determined by the model for end-stage liver disease (MELD) score, the quality of organs used is subject to physician discretion. We aimed to determine whether implementation of MELD affected the quality of organs transplanted, the type of patients who receive the higher-risk organs, and the impact of these changes on their posttransplant survival. Data were analyzed from the United Network for Organ Sharing of adults who underwent deceased-donor liver transplantation between January 1, 2007, and August 1, 2007 (n = 47,985). Dependent variables included the donor risk index (a continuous variable that measures the risk of graft failure associated with a particular organ) and patient survival after transplantation. The overall organ quality of transplanted livers has worsened since MELD implementation, with an increase in the donor risk index equivalent to a 4% increased risk of graft failure after adjusting for temporal trends (P < .001). This was accompanied by a shift from using the higher-risk organs in the more urgent patients (in the pre-MELD era) to using the higher-risk organs in the less urgent patients (in the post-MELD era). Posttransplant survival has worsened over time (hazard ratio, 1.017/y; P = .005) among the less urgent patients (MELD scores, <20); mediation analysis suggests this change in survival was caused primarily by changes in organ quality. As an unintended consequence of the MELD allocation policy, patients that are least in need of a liver transplant now receive the highest-risk organs. This has reduced posttransplant survival in recent years among patients with low MELD scores.