Global, regional, and national burden of multiple sclerosis from 1990 to 2021 and projections to 2040: A comprehensive analysis from the global burden of disease study.

BACKGROUND

Multiple sclerosis (MS) is a leading cause of neurological disability in young adults, with a striking female predominance. Understanding of its temporal and geographic patterns is crucial for informing public health strategies.

METHODS

Data from the Global Burden of Disease (GBD) 2021 study were used to assess the burden of MS from 1990 to 2021 at global, regional, and national levels. Estimates of incidence, deaths, and disability-adjusted life years (DALYs) were stratified by age, sex, and Socio-demographic Index (SDI). Temporal trends were evaluated using the estimated annual percentage change (EAPC). Bayesian Age-Period-Cohort (BAPC) modeling was employed to forecast the burden through 2040. Additionally, frontier analysis, decomposition analysis, inequality assessment, and estimation of the smoking-attributable burden were conducted.

RESULTS

Between 1990 and 2021, the absolute numbers of MS incident cases, deaths, and DALYs increased globally due to population growth and aging. In contrast, age-standardized incidence rates remained relatively constant, while both age-standardized mortality and DALYs rates experienced modest declines. Females consistently bore a higher burden across all metrics and age groups. Frontier analysis revealed significant performance gaps, and BAPC projections suggested a continued gradual decline in global age-standardized mortality and DALY rates through 2040. Despite these encouraging trends, smoking remained a substantial modifiable risk factor.

CONCLUSION

MS continues to impose a significant global burden, with persistent regional and socioeconomic disparities. This highlights the necessity for targeted public health strategies, including early diagnosis, accessible treatment, functional rehabilitation, and preventive measures such as smoking cessation, to reduce disparities and optimize outcomes worldwide.