The new liver allocation score (LivAS) for transplantation is validated in germany improving transplant survival benefit but not in the UK

BACKGROUND: Prognostic models for the prediction of 90-day mortality after transplantation with pre-transplant donor and recipient variables are needed to calculate transplant benefit.

METHODS AND FINDINGS: Transplants in adult recipients in Germany (Hannover (n=770), Kiel (n=234)) and the UK (Birmingham (n=829)) were used for prognostic model design and validation in separate training and validation cohorts. Survival benefit of transplantation was estimated by subtracting observed post-transplant 90-day mortality from expected 90-day mortality without transplantation determined with the MELD-Score. A prognostic model (LivAS) was derived using a randomised sample from Hannover using pre-transplant donor and recipient variables. This model could be validated in the German training and validation cohorts (AUROCs: >0.70) but not in the English cohort (AUROC: 0.58). Although 90-day mortality rates after transplantation were 13.7% in Hannover, 12.1% in Kiel and 8.3% in Birmingham, the calculated 90-day survival benefits of transplantation were 6.8% in Hannover, 7.8% in Kiel and 2.8% in Birmingham. Deployment of the LivAS for limiting allocation to donor and recipient combinations with likely 90-day survival as indicated by pre-transplant LivAS values below cut-off would have increased the survival benefit to 12.9% in the German cohorts while this would have decreased in England to 1.3%. The English and German cohorts revealed significant differences in 21 of 28 pre-transplant variables.

CONCLUSIONS: The LivAS could be validated in Germany and may improve German allocation policies leading to greater survival benefits while validation failed in England due to profound differences in selection criteria for liver transplantation. This study suggests the need for national prognostic models. Even though the German centers had higher rates of 90-day mortality, estimated survival benefits were greater. This article is protected by copyright. All rights reserved.