Prevalence of multiple sclerosis in Iran by 2040: a national and subnational modelling study

Multiple sclerosis (MS) is a chronic neurological condition that significantly contributes to disability in young adults globally. In Iran, the prevalence of MS has sharply increased, presenting substantial public health and economic challenges that highlight the necessity for comprehensive epidemiological data to anticipate the future burden of MS. This study employed an illness-death model (IDM) to project MS prevalence in Iran through 2040, using historical epidemiological data from the Global Health Data Exchange (GHDx) and population statistics from the Statistical Centre of Iran (SCI). Projections were made separately for males, females, and the overall population at both national and levels. Nationally, the age-standardized prevalence rate (ASPR) of MS is projected to increase from 55.30 per 100,000 in 2021 to 58.13 per 100,000 in 2040, marking a 5.11% increase. Females are expected to experience a more substantial increase compared to males (6.4% vs. 2.9%). Provincially, Isfahan and Fars are anticipated to exhibit the highest ASPRs in 2040, while Sistan and Baluchistan, historically a low-prevalence region, is projected to witness the most significant percentage increase (20.01%). Our results reveal an increasing burden of MS in Iran, with notable regional and gender disparities. These findings underscore the need for targeted public health interventions, equitable resource distribution, and enhanced healthcare infrastructure to support underserved areas and implement gender-specific health strategies to mitigate the long-term effects of MS.