Understanding the Humanistic Burden of Metabolic Dysfunction-Associated Steatohepatitis Liver Disease in the US Population: Age/Sex Stratified Analysis of Morbidity and Mortality

BACKGROUND AND AIMS: Metabolic dysfunction-associated steatohepatitis (MASH) is defined by a buildup of fat in the liver and signs of inflammation and liver damage (fibrosis). Eventually, subjects with MASH may develop cirrhosis, leading to more serious consequences of decompensation, liver cancer, and liver failure. In this manuscript, a population-level burden-of-disease model for MASH in the USA is constructed that may form a novel framework to assess the value of new population-level diagnostic and treatment strategies for MASH as they emerge. METHODS: We develop an underlying model of MASH, similar to published models in literature, nested within a population model. Using this model, we estimate the likely incidence of MASH at the stage at which it is most indolent and difficult to detect through calibration techniques and published prevalence of later disease stages. We then present a graphical analysis of disease burden, including disaggregating this burden by age and sex, and into the relative contribution of morbidity and mortality. RESULTS: From the model, we realised that MASH has a higher burden if acquired earlier in life, and the decade in which burden is greatest for patients with MASH is dependent on the age at which they contracted the disease: aged < 40: eighth decade (ages 70-79 years) and aged > 40: ninth decade (80-89 years). The model also found that the burden was higher for women owing to their longevity. Similarly at the population level, the greatest burden of MASH is expected to fall in the 70-79-year-old age group (6.46 million years of quality-adjusted life-expectancy [QALE]) and the 60-69-year-old age band (5.49 million years of QALE). Approximately 19.34 million years of QALE are lost in the US population (334 million) over their lifetime. CONCLUSIONS: The analysis shows that mortality is a greater burden than morbidity for MASH, and that owing to the insidious nature of the disease, burden is likely to be concentrated in the seventh to eighth decade of life (60-79-year-olds). The burden for females is higher than for males, without differential incidence, owing to women's longevity. The incidence of MASH is expected to rise owing to the increasing prevalence of obesity and diabetes in the population.