Development of a Widely Applicable and Simple Prognostic Score for Patients with Acute-on-chronic Liver Failure.

Background and Aims: Acute-on-chronic liver failure (ACLF) tends to progress rapidly with high short-term mortality. We aimed to create a widely applicable, simple prognostic (WASP) score for ACLF patients. Methods: A retrospective cohort of ACLF cases recruited from three centers in China were divided into training and validation sets to develop the new score. A prospective longitudinal cohort was recruited for further validation. Results: A total of 541 cases were included in the training set, and seven independent ACLF prognostic factors were screened to construct a new quantitative WASP-ACLF table. In the validation set of 671 cases, WASP-ACLF showed better predictive ability for 28-day and 90-day mortality than the currently used prognostic scores at baseline, day 3, week 1, and week 2. The predictive efficacy and clinical validity of the model improved over time. Patients were assigned to low-, intermediate-, and high-risk groups by their WASP-ACLF scores. Compared with the other two groups, intermediate-risk patients had a more uncertain prognosis, with a 90-day mortality of 44.4-50.6%. Sequential assessments at weeks 1 and 2 found the 90-day mortality of intermediate-risk groups was <20% for patients with a ≥2 point decrease in WASP-ACLF and was up to 56% for patients with a ≥2 points increase. Similar results were observed in prospective data. Conclusions: The new ACLF prognostic score was simple, widely applicable, and had good predictive efficacy. Continuous assessments and trend of change in WASP-ACLF need to be considered, especially for intermediate-risk patients.