Abstract: Objective To explore the value of Prognostic Nutritional Index (PNI) combined with the Model for End Stage Liver Disease (MELD) score in assessing 1the 1-year mortality risk in patients with decompensated cirrhosis. Methods A total of 216 patients diagnosed with decompensated cirrhosis in our hospital from January 2020 to January 2023 were retrospectively included. Death was regarded as the terminal event. Patients were categorized into a survival cohort (156 cases) and a deceased cohort (60 cases) based on the outcome of 1-year follow-up. The differences in PNI, Child-Pugh score, and MELD level at admission between the two groups were compared. Univariate and multivariate Cox proportional hazards models were used to predict the independent factors influencing 1-year mortality in patients. Receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was evaluated for comparison. The optimal cut-off value of PNI was calculated according to the Youden index, and Kaplan-Meier curves were constructed to analyze the 1-year survival rate of patients with different PNI levels. Logistic regression was used for joint prediction of the value of PNI and MELD score in predicting 1-year mortality in patients. Finally, the non-linear association between PNI and 1-year mortality risk was evaluated using restricted cubic spline (RCS) fitted Cox regression models. Results 60 cases (27.78%) died during the 1-year follow-up. The PNI at admission was significantly decreased in the death group compared to the survival group(29.0 (25.7～31.7)vs. 36.5 (30.6～41.0) , P＜0.001). PNI was negatively correlated with Child-Pugh score (r=-0.766, P＜0.001) and MELD score (r=-0.483, P＜0.001). PNI were independent factors predicting the 1-year mortality risk (OR:0.938, 95%CI:0.889~0.991, P=0.021). ROC curves showed that the optimal cut-off values for predicting 1-year mortality risk were 33.45 for PNI and 16.61 for MELD score, with AUC of 0.780 and 0.871, respectively (P<0.001); while the combination of PNI and MELD score improved the efficiency of predicting 1-year mortality in patients ( AUC=0.885, P<0.001). The RCS graph showed a linear relationship between PNI and 1-year mortality risk (P for nonlinear＞0.05). Conclusion The joint utilization of PNI and MELD score proves to be effective in forecasting the risk of 1-year mortality in patients suffering from decompensated cirrhosis.

Key words: Liver cirrhosis, Prognostic Nutritional Index, MELD score