The need for such a review is heightened by the lack and infeasibility of RCTs on this topic and the fact that considerable debate over the value of MELD in this context remains. However, it has yet to be assessed through a systematic review and critical appraisal of published studies that adheres to internationally accepted systematic review guidelines. In recent years, the possibility of using pre-transplant MELD to predict post-transplant survival has been explored in many opinion pieces and expert reviews. An ideal system would allocate organs to patients not only at the highest risk of dying without transplantation, but also with the highest likelihood of survival following transplantation. It uses objective variables (creatinine, bilirubin and the international normalized ratio of prothrombin time (PTINR)) to quantify the severity of ESLD, enabling the prioritization of patients in need of liver transplantation by medical urgency. The MELD score was initially developed by Malinchoc et al to predict mortality in patients undergoing transjugular intrahepatic portosystemic shunts, but has since been validated as predictor of short-term mortality in patients awaiting transplantation. First adopted by the United States in February 2002, it has become one of the most widely used approaches to prioritizing liver transplant candidates in countries around the world.

In order to minimize waitlist mortality, a Model for End-Stage Liver Disease (MELD) - based organ allocation was proposed. However, the supply of donor livers remains inadequate to meet the demand, necessitating an effective policy for organ allocation. Liver transplantation offers the only curative therapy for patients with end-stage liver disease (ESLD). The identification of patients who are most likely to benefit from orthotopic liver transplantation (OLT) is a significant challenge in transplantation medicine. Therefore, their findings should be interpreted conservatively. In summary, while the majority of studies reported an association between pre-transplantation MELD score and post-transplant survival, they represented a low level of evidence. Values were below 0.7 in all but two studies, suggesting poor predictive value. Eleven studies also measured predictive ability with c-statistics.

In the remaining 22, some association was found. In 15 studies, no statistically significant association between MELD and post-transplant survival was found. There was significant clinical heterogeneity in patient populations across studies, which precluded performance of a meta-analysis. They represented 15 countries and a total of 53,691 patients. Studies were all case series that typically involved stratified analyses of survival by MELD. Thirty-seven studies met these criteria and were included in the review. Any study examining the relationship between pre-transplant MELD and post-transplant survival in the general transplant population was included. There were 3058 discrete citations identified and screened for possible inclusion. PubMed, the Cochrane Library, Embase, and Web of Science were searched for articles published in the English language since 2005 using a structured search strategy. A systematic review and critical appraisal was performed using Cochrane guidelines. The purpose of this study was to examine the predictive value of the pre-transplantation MELD score on post-transplant survival from relevant existing studies. MELD has been validated as a predictor of wait-list mortality in transplantation candidates and has been postulated as a predictor of post-transplant survival. The model for end-stage liver disease (MELD) score is used to stratify candidates for liver transplantation based on objective measures of disease severity.

Pre meld definition