In the Australian study cohort, the addition of SF to MELD increased the area under the ROC curve by 7.6% and 7.5% for 180-day and 1-year survival, respectively; however, these differences did not reach statistical significance (P = 0.10, P = 0.10, respectively). Thus, in this cohort, our findings are similar to that described by Biggins et al.,9 who evaluated the role of serum sodium concentration in predicting liver Sorafenib cost transplant waiting list mortality. In that study, the investigators showed that a low serum sodium concentration was a significant, independent factor predicting increased mortality and that the addition of sodium to MELD increased the area under the ROC curve at

each time point studied. However, akin to our study, the differences failed to reach statistical significance. A complete understanding of the value of adding sodium concentration to MELD in predicting waiting

list mortality was provided when Kim et al. evaluated over 2000 patients registered with the Organ Procurement and Transplantation Network.14 In the current study, we provide further evidence Target Selective Inhibitor Library in a validation cohort of patients undergoing OLT in a center in the United States that SF increases the accuracy in predicting liver transplant waiting list mortality. The addition of SF to MELD increases the area under the ROC curve for 180-day and 1-year mortality by 21.4% and 40.3%, respectively, for patients in the validation cohort. These increases were greater than in the Australian cohort and were highly statistically significant (P = 0.001, P < 0.00001, respectively). Further evidence of the importance of SF was demonstrated by our observation that increments in SF of 50 μg/L and 100 μg/L were associated with an increased risk of death on the waiting list for both Australian and USA patients. Moreover, an SF greater than 500 μg/L and MELD were the only factors associated 上海皓元 with increased mortality in multivariate analysis in the validation cohort. We propose on the basis of the results presented in this study that a multicenter study evaluating the role of SF similar to that conducted by Kim et al.14 in relation

to serum sodium concentration is now clearly required. In the univariate analysis of the study population, MELD was significantly associated with an adverse outcome for 180-day and 1-year survival, although the HRs were modestly increased at 1.09 and 1.10, respectively. It is curious that MELD did not remain an independent predictor of mortality in the multivariate analysis for 180-day and 1-year survival in the Australian cohort. In contrast, MELD was identified as an important predictor of mortality by multivariate analysis in the USA cohort for 180-day and 1-year survival. This is an interesting observation that requires careful consideration and is possibly explained by differences between the two populations. The mean MELD of the study population (15.4) was significantly lower than in the USA cohort (19.