Association of Index and Changes in Fibrosis-4 Score With Outcomes in Metabolic Dysfunction-Associated Steatohepatitis.

This study assessed the relationship between Fibrosis-4 (FIB-4) scores at time of initial metabolic dysfunction-associated steatohepatitis (MASH) diagnosis, as well as subsequent changes in these scores over time, and any adverse hepatic and extrahepatic outcomes. This study retrospectively analyzed administrative claims data from patients with a MASH diagnosis between 2015 and 2022. Patients were categorized based on risk of advanced fibrosis (low, indeterminate, and high) using FIB-4 score calculated at index (date of FIB-4 score within ±180 days of MASH diagnosis) and longitudinally. Adjusted hazard ratios (aHRs) and confidence intervals (CIs) were estimated to determine associations between index and longitudinal changes in FIB-4, and hazard of major adverse liver outcomes (MALO) and major adverse cardiovascular events (2-point assessment; MACE-2pt). A total of 17,511 and 19,395 patients with an index FIB-4 score were included in the MALO and MACE-2pt analyses, respectively. Cohorts with longitudinal FIB-4 scores comprised 10,655 and 11,934 patients for the 2 respective outcomes. High-risk FIB-4 score at index was significantly associated with higher hazard of MALO (aHR: 4.29; 95% CI: 3.87-4.77) and MACE-2pt (aHR: 1.44; 95% CI: 1.25-1.66) compared with low risk. Progression from low-risk to high-risk FIB-4 score was associated with a higher hazard of MALO (aHR: 2.62; 95% CI: 1.92-3.58), vs remaining at low risk. This was also found for progression from indeterminate-risk to high-risk FIB-4 score (aHR: 1.94; 95% CI: 1.50-2.53). High-risk index FIB-4 and increases in FIB-4 are associated with increased hazard of MALO and MACE. Thus, in patients diagnosed with MASH, FIB-4 scores could serve as an important noninvasive and prognostic tool for adverse cardiovascular and liver outcomes.