To evaluate the effects of laboratory indexes, such as lymphocyte-prothrombin time ratio (LPR) and fibrinogen-albumin ratio index (FARI), on clinical prognosis of liver failure, and to establish a novel prognostic model for liver failure.

Clinical data of 1 114 patients with liver failure admitted to the Third Affiliated Hospital of Sun Yat-sen University from June 2017 to December 2020 were retrospectively analyzed. The informed consents of all patients were obtained and the local ethical committee approval was received. Among them, 899 patients were male and 215 female, aged from 18 to90 years, with a median age of 46 years. Hematological indexes, liver function indexes, coagulation function indexes and baseline clinical characteristics of patients with liver failure upon the initial admission were collected. The 90-d mortality after the diagnosis of liver failure was considered as the prognostic outcome. All patients were divided into the modeling and validation groups according to the ratio of 7:3. The factors affecting clinical prognosis of liver failure were screened by Lasso regression analysis and subject to 10-fold cross-validation. The influencing factors were included in Logistic regression analysis to establish a prediction model. The area under the ROC curve (AUC) was used to evaluate the discrimination degree of this prediction model, and the Hosmer-Lemeshow (H-L) index was employed to evaluate the calibration degree.

Among1 114 liver failure patients, 317 cases died within postoperative 90 d, with a mortality rate of 28.46%(317/1 114). Lasso regression analysis showed that LPR, prothrombin time activity (PTA), Na, TB, FARI, PT, absolute value of neutrophil (NEU) and age (Age) were critical prognostic factors of liver failure. A prediction model of LPTFA was established. Logit P=-1.75-6.57×LPR(10⁹/L·sec)-0.04×PTA(%)-0.006×Na(mmol/L)+0.001×TB(μmol/L)+0.08×FARI(%)+0.009×PT(sec)+0.03×NEU(10⁹/L)+0.04×Age. A nomogram was delineated to predict the 90-d mortality of patients with liver failure. The specificity and sensitivity of this model were 0.74 and 0.56. The AUC of this model was 0.704 (95%CI: 0.660-0.740), significantly higher than 0.612 (95%CI: 0.570-0.650) of MELD score (Z=4.207, P<0.001). In the validation group, the AUC of LPTFA model was 0.686 (95%CI: 0.620-0.750), significantly higher than 0.563 (95%CI: 0.49-0.64) of MELD score (Z=3.143, P=0.001 7). H-L index validated that P=0.41 in the modeling group, and P=0.19 in the validation group, and the H-L indexes in two groups were both greater than 0.05, indicating that the model calibration degree was relatively high.

Compared with MELD score, the prediction model for liver failure established based on LPR and FARI has better prediction value and is more reliable.