METHODS: We analyzed data from 3004 individuals with biopsy-proven metabolic dysfunction-associated steatotic liver disease (MASLD) across 29 Chinese and 9 international cohorts to validate the acMASH index and develop the acFibroMASH index. Additionally, we utilized the independent external data from a multi-national cohort of 9034 patients with MASLD to examine associations between the acFibroMASH index and the risk of LREs.

RESULTS: In the pooled global cohort, the acMASH index identified MASH with an area under the receiver operating characteristic curve (AUROC) of 0.802 (95% confidence interval [CI], 0.786-0.818). The acFibroMASH index (including the acMASH index plus liver stiffness measurement) accurately identified fibrotic MASH with an AUROC of 0.808 in the derivation cohort and 0.800 in the validation cohort. Notably, the AUROC for the acFibroMASH index was 0.835 (95% CI, 0.786-0.882), superior to that of the FAST score at 0.750 (95% CI, 0.693-0.800; P < .01) in predicting the 5-year risk of LREs. Patients with acFibroMASH >0.39 had a higher risk of LREs than those with acFibroMASH <0.15 (adjusted hazard ratio, 11.23; 95% CI, 3.98-31.66).