AIM: To establish a new model for predicting survival in acute-on-chronic liver failure(ACLF) patients treated with an artificial liver support system. METHODS: One hundred and eighty-one ACLF patients who were admitted to the hospital from January 1, 2012 to December 31, 2014 and were treated with an artificial liver support system were enrolled in this retrospective study, including a derivation cohort(n = 113) and a validation cohort(n = 68). Laboratory parameters at baseline were analyzed and correlatedwith clinical outcome. In addition to standard medical therapy, ACLF patients underwent plasma exchange(PE) or plasma bilirubin adsorption(PBA) combined with plasma exchange. For the derivation cohort, KaplanMeier methods were used to estimate survival curves, and Cox regression was used in survival analysis to generate a prognostic model. The performance of the new model was tested in the validation cohort using a receiver-operator curve.RESULTS: The mean overall survival for the derivation cohort was 441 d(95%CI: 379-504 d), and the 90- and 270-d survival probabilities were 70.3% and 58.3%, respectively. The mean survival times of patients treated with PBA plus PE and patients treated with PE were 531 d(95%CI: 455-605 d) and 343 d(95%CI: 254-432 d), respectively, which were significantly different(P = 0.012). When variables with bivariate significance were selected for inclusion into the multivariate Cox regression model, number of complications, age, scores of the model for end-stage liver disease(MELD) and type of artificial liver support system were defined as independent risk factors for survival in ACLF patients. This new prognostic model could accurately discriminate the outcome of patients with different scores in this cohort(P < 0.001). The model also had the ability to assign a predicted survival probability for individual patients. In the validation cohort, the new model remained better than the MELD.CONCLUSION: A novel model was constructed to predict prognosis and accurately discriminate survival in ACLF patients treated with an artificial liver support system. AIM: To establish a new model for predicting survival in acute-on-chronic liver failure (ACLF) patients treated with an artificial liver support system. METHODS: One hundred and eighty-one ACLF patients who admitted to the hospital from January 1, 2012 to December 31, 2014 and were treated with an artificial liver support system were enrolled in this retrospective study, including a derivation cohort (n = 113) and a validation cohort (n = 68). Laboratory parameters at baseline were analyzed and correlated with clinical In addition to standard medical therapy, ACLF patients underwent plasma exchange (PE) or plasma bilirubin adsorption (PBA) combined with plasma exchange. For the derivation cohort, Kaplan Meier methods were used to estimate survival curves, and Cox regression was used in survival The performance of the new model was tested in the validation cohort using a receiver-operator curve .RESULTS: The mean overall survival for the de rivation cohort was 441 d (95% CI: 379-504 d), and the 90- and 270-d survival probabilities were 70.3% and 58.3%, respectively. The mean survival times of patients treated with PBA plus PE and patients treated with PE were 531 d (95% CI: 455-605 d) and 343 d (95% CI: 254-432 d), respectively, which were significantly different (P = 0.012). When variables with bivariate significance were selected for inclusion into the multivariate Cox regression model, number of complications, age, scores of the model for end-stage liver disease (MELD) and type of artificial liver support system were defined as independent risk factors for survival in ACLF patients. This new prognostic model could be accurately discriminate the outcome of patients with different scores in this cohort (P <0.001). The model also had the ability to assign a predicted survival probability for individual patients. In the validation cohort, the new model remained better than the MELD.CONCLUSION: A novel model was constructed to predictprognosis and precisely discriminate survival in ACLF patients treated with an artificial liver support system.