The economic burden of non-alcoholic fatty liver disease in Sri Lanka: a 35-year Markov model analysis

Non-alcoholic fatty liver disease (NAFLD) poses a growing health-economic challenge for developing countries. This study quantifies the long-term economic burden of NAFLD in Sri Lanka, examining disease progression, healthcare costs, and productivity losses. Using a Markov model simulating NAFLD progression from 2007 to 2042 in the population aged 35+, we analysed nine disease stages from early NASH to liver transplant. The model incorporated obesity trends, age variations, and diabetes comorbidity, with costs calculated in 2024 Sri Lankan Rupees and USD. A one-year cycle length was applied. Epidemiological inputs (prevalence and incidence) were derived from published Sri Lankan community-based cohorts, transition probabilities were adapted from published stage-specific matrices, and direct costs were obtained from local specialist consensus and private-sector hospital tariffs. Deterministic sensitivity analysis was performed using an alternative published transition matrix. All modelling, cost aggregation and analyses were performed in Microsoft Excel (Microsoft 365), with R (version 4.3.1) used for cross-checking matrix computations. Results show the NAFLD population doubling by 2042, reaching 53% of the 35 + population. Average annual per-patient costs in 2024 range from USD 82 for early NASH to USD 377 for advanced stages. The total economic burden in 2023 is estimated at USD 668 million (0.8% of GDP) for NAFLD alone, rising to USD 1.2 billion (1.4% of GDP) when including diabetes comorbidity. This analysis highlights the urgent need for prevention and early intervention strategies.