The Growing Economic and Clinical Burden of Nonalcoholic Steatohepatitis (NASH) in the United States

Background: Nonalcoholic steatohepatitis (NASH) is a cause of chronic liver disease. Aim: Model the burden of NASH in the United States according to obesity. Metbods: The discrete-time Markov model comprised adult NASH subjects moving through 9 health states and 3 absorbing death states (liver, cardiac, and other deaths) with 1-year cycles anda 20-year horizon. Given that reliable natural history data for NASH are not available, tran-sition probabilities were estimated from the literature and population-based data. These rates were disaggre-gated to determine age-obesity group rates by applying estimated age-obesity patterns. The model considers 2019 prevalent NASH cases and new incident NASH cases (2020-2039), assuming that recent trends will continue. Annual per-patient costs by health state were based on published data. Costs were standardized to 2019 US dol-lars and inflated by 3% annually. Results: NASH cases in the United States are forecasted to increase by +82.6%, from 11.61 million (2020) to 19.53 million (2039). During the same period, cases of advanced liver disease increased +77.9%, from 1.51 million to 2.67 million, while its proportion remained stable (13.46%-13.05%). Similar patterns were observed in both obese and non-obese NASH. Among NASH, 18.71 million overall deaths, 6.72 million cardiac-specific deaths, and 1.71 million liver-specific deaths were observed by 2039. During this period, the projected cumulative direct healthcare costs were $1208.47 billion (obese NASH) and $453.88 billion (non-obese NASH). By 2039, the projected NASH attributable healthcare cost per patient increased from $3636 to $6968. Conclusions: There is a substantial and growing clinical and economic burden of NASH in the United States. ( J CLIN EXP HEPATOL 2023;13:454-467)