Epidemiological and socio-economic burden of MASH (previously known as NASH) in Europe: a systematic literature review

Background and aims Metabolic dysfunction-associated steatohepatitis (MASH) in the past known as non-alcoholic steatohepatitis (NASH) is a chronic liver disease that poses significant epidemiological, clinical and socio-economic challenges. Given the limited availability of data on disease burden, this systematic literature review aimed to describe epidemiology, mortality, quality of Life (QoL) and socio-economic burden associated with NASH/MASH.Methods A systematic literature review was carried out in PubMed (Medline) and Embase using the terms "NASH/MASH" and terms related to epidemiology, mortality, QoL and resource utilization and costs. The search covered publications from January 1, 2014, to January 16, 2024, and was restricted to articles published in English, Italian and Spanish. A two steps screening phase was performed, and relevant data were extracted from the included articles following a full-text assessment.Results Among the retrieved studies, 25 included epidemiological data, 14 addressed mortality, 11 focused on QoL, and 9 focused on resource utilization and economic burden. Within the different populations assessed, the prevalence of NASH/MASH ranged from 18% to 68%. Diagnosis of NASH/MASH was associated with increased mortality, reduced QoL and higher use of healthcare resources. Advanced stages of disease were associated with further deterioration of QoL and increased use of healthcare facilities. Hospitalization is the main cost driver, followed by outpatients visit and therapies. Annual costs per patient varied geographically, from 4,994 & euro; in Italy to 9,541 & euro; in the UK, with advanced stages associated with significantly higher costs.Conclusion The findings revealed that MASH poses a significant epidemiological, clinical and socio-economic burden on the NHS and society. The marked heterogeneity across available studies underscores the need for updated research adopting the current disease definition. Further evidence is required to better characterise disease burden across stages of severity and to inform the development and implementation of effective strategies for improved disease management.