Progression from Non-alcoholic Steatohepatitis to Advanced Liver Diseases and Mortality Among Medicare Patients.

Introduction: Non-alcoholic steatohepatitis (NASH) may progress to more advanced liver disease. This study aimed to characterize NASH progression and mortality in the Medicare population.

Methods: Patients with NASH in 100% Medicare fee-for-service claims accrued from 2015-2021 who were ≥ 66 years old at index diagnosis, continuously enrolled for ≥ 12 months prior to and ≥ 6 months following index (unless death), and had no evidence of other causes of liver disease were included. Diagnosis codes defined severity states: non-cirrhotic NASH, compensated cirrhosis (CC), decompensated cirrhosis (DCC), hepatocellular carcinoma (HCC), and liver transplant (LT). Survival analyses of disease progression and mortality were conducted for each state and by year of progression (Y1-5). Cox proportional hazards models assessed risk factors of worsening disease.

Results: Mean age and follow-up were 72.2 and 2.8 years in 14,806 unique patients (n = 12,990 NASH; 1899 CC; 997 DCC; 209 HCC; 140 LT). Progression rates were highest for patients with CC (11-37% for Y1-5), followed by DCC (3-18%), NASH (3-12%), and HCC (2-4%). Mortality rates were highest for patients with HCC (41-85% for Y1-5), followed by DCC (41-76%), LT (7-33%), CC (6-26%), and NASH (2-12%). Patients with any disease progression had a 5-year mortality rate more than double that of patients without progression (41% vs. 16%). Delayed progression from NASH was associated with lower mortality risk; the 5-year mortality rate was 26% lower for patients with progression in Y2 vs. Y1 (32% vs. 43%) and further decreased for progression in Y3-Y5. Risk factors included age, nursing home use, congestive heart failure, coagulopathy, fluid/electrolyte disorders, and unexplained weight loss.

Conclusion: Medicare patients ≥ 66 years with NASH experience high risk of disease progression associated with increased mortality rates. Slower disease progression is associated with lower mortality rates, suggesting that therapies that can delay or prevent NASH progression may reduce morbidity and mortality.