Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) and is strongly associated with type 2 diabetes mellitus (T2DM). Patients with both T2DM and NASH have increased risk for adverse clinical outcomes, leading to higher risk for mortality and morbidity. We built a Markov model with 1-year cycles and 20-year horizon to estimate the economic burden of NASH with T2DM in the U.S.
Cohort size was determined by population size, prevalence of T2DM, and prevalence and incidence of NASH in 2017. The model includes 10 health states—NAFL, NASH fibrosis stages F0 through F3, compensated and decompensated cirrhosis, hepatocellular carcinoma, 1 year post–liver transplant, and post–liver transplant—as well as liver-related, cardiovascular, and background mortality. Transition probabilities were calculated from meta-analyses and literature. Annual costs for NASH and T2DM were taken from literature and billing codes.
We estimated that there were 18.2 million people in the U.S. living with T2DM and NAFLD, of which 6.4 million had NASH. Twenty-year costs for NAFLD in these patients were $55.8 billion. Over the next 20 years, NASH with T2DM will account for 65,000 transplants, 1.37 million cardiovascular-related deaths, and 812,000 liver-related deaths.
This model predicts significant clinical and economic burden due to NASH with T2DM over the next 20 years. In fact, this burden may be greater since we assumed conservative inputs for our model and did not increase costs or the incidence of T2DM over time. It is highly likely that interventions reducing morbidity and mortality in NASH patients with T2DM could potentially reduce this projected clinical and economic burden.