The survival outcomes following liver transplantation (SOFT) score: validation with contemporaneous data and stratification of high-risk cohorts

Abstract

Models to project survival after liver transplantation are important to optimize outcomes. We introduced the survival outcomes following liver transplantation (SOFT) score in 2008 (1) and designed to predict survival in liver recipients at three months post-transplant with a C statistic of 0.70. Our objective was to validate the SOFT score, with more contemporaneous data from the OPTN database. We also applied the SOFT score to cohorts of the sickest transplant candidates and the poorest-quality allografts. Analysis included 21 949 patients transplanted from August 1, 2006, to October 1, 2010. Kaplan-Meier survival functions were used for time-to-event analysis. Model discrimination was assessed using the area under the receiver operating characteristic (ROC) curve. We validated the SOFT score in this cohort of 21 949 liver recipients. The C statistic was 0.70 (CI 0.68-0.71), identical to the original analysis. When applied to cohorts of high-risk recipients and poor-quality donor allografts, the SOFT score projected survival with a C statistic between 0.65 and 0.74. In this study, a validated SOFT score was informative among cohorts of the sickest transplant candidates and the poorest-quality allografts.

Keywords: SOFT score; high-risk; liver transplantation; patient survival.