Prediction of 6-month survival after liver transplantation using cox regression

Background. The outcome of liver transplantation (LTx) has been correlated with several donor and recipient factors. Methods. A database of 191 consecutive LTx cases was analyzed using Kaplan-Meier and Cox regression statistics based on 80 variables. To avoid additional effects of late events on patient survival, the chosen endpoint was 6 months. Data were evaluated using SPSS statistical software. Results. Kaplan-Meier analysis revealed a difference in 1- to 6-month graft survival between patients transplanted with organs from donors older versus younger than 60 years (Breslow, P < .01). Differences in 1- to 6-month graft survivals were observed between patients listed as UNOS status 3, 2B, 2A, and 1: the outcomes for UNOS status 2B versus UNOS status 2A and UNOS status 2B versus status 1 were significant (P < .05). Differences in 1- to 6-month graft survival rates were found between patients with versus without sepsis (P < .05), and with versus without rejection episodes (P < .01). Cox regression analysis revealed only three of the variables to be independent prognostic predictors of graft failure: donor age; postoperative septic status; and rejection. The best mathematical multivariate Cox regression model linked donor age + donor Na + rejection + sepsis to 1- to 6-month graft survival (chi-square = 29.06, P < .001). Conclusion. Factors predictive of 1- to 6-month graft survival after liver transplantation include donor age; UNOS status; sepsis; and rejection.