Introduction
Over the past few decades, multiple sclerosis (MS) has gained significant attention in the medical community due to its increasing prevalence and impact on public health. This study delves into the global trends of MS incidence, mortality, and disability-adjusted life years (DALYs) among adults aged 20–54 years from 1990 to 2021, with projections extending to 2035. Utilizing data from the Global Burden of Disease (GBD) study, this analysis provides a comprehensive overview of MS’s evolving epidemiology.
Methods
The study employed data from the GBD database, covering 204 countries and territories. The analysis was stratified by age, sex, and geographical location. Annual percentage changes (APC) were calculated using Joinpoint regression, while estimated annual percentage changes (EAPC) were derived through log-linear regression modeling. Bayesian age-period-cohort (BAPC) modeling was used to forecast future disease burden.
Findings
In 2021, there were approximately 51,904 new MS cases globally, with 4,738 deaths and 512,986 DALYs. From 1990 to 2021, the global incidence of MS increased by 49.48%, mortality rose by 18.21%, and DALYs increased by 43.22%. The High Socio-Demographic Index (SDI) region reported the highest rates of incidence, mortality, and DALYs. Western Europe had the highest number of cases, while the United States reported the most incident cases in 2021. Sweden had the highest national incidence rate.
Interpretation
The global burden of MS has shown increasing trends, with significant variations across different SDI regions. Understanding these epidemiological trends is crucial for enhancing global disease prevention and control efforts. MS is a prevalent autoimmune disorder characterized by relapsing–remitting and progressive forms, leading to significant healthcare expenditures and impaired employment prospects.
Epidemiological Trends
Globally, MS cases increased from approximately 2.2 million in 2016 to 2.8 million in 2020. Region-specific trends illustrate this rise, with notable increases in southern Norway and northeastern Italy. Individuals of Northern European descent exhibit a higher disease risk, with prevalence rates decreasing as distance from the equator increases. Studies from the Middle East also indicate sharp increases in MS incidence, highlighting the disease as a significant global public health issue.
Global Burden of Disease Study
The GBD study, coordinated by the Institute for Health Metrics and Evaluation (IHME), provides a comprehensive epidemiological framework. It quantifies health losses from diseases, injuries, and risk factors, enabling comparative assessments across countries and regions. The study utilizes three principal metrics: incidence, mortality, and DALYs, integrating years of life lost due to premature mortality and years lived with disability.
Bayesian Age-Period-Cohort Modeling
The BAPC model addresses the complexity and high dimensionality of large epidemiological datasets. It extends traditional generalized linear models within a Bayesian framework, dynamically integrating age, period, and cohort effects. This approach enhances computational efficiency and is particularly suitable for long-term projections of disease burden.
Results and Analysis
The analysis reveals significant shifts in the global epidemiology of MS. Incidence rates initially declined and then rose, with the lowest APC observed globally from 1992 to 1995. Gender differences were evident, with females surpassing males in incidence rates from 20 to 49 years. Mortality rates initially rose and then declined, with the highest APC observed between 1990 and 1993. DALYs showed a similar trend, with an initial increase followed by a decline.
Regional and National Trends
In 2021, the High SDI region reported the highest incidence of MS, with a significant increase from 1990. The Low SDI region experienced the largest increase in deaths. Among geographic regions, Western Europe had the highest MS-related mortality and DALYs. The United States reported the most MS incident cases, while Sweden had the highest national incidence rate.
Projections to 2035
Using the BAPC model, projections indicate a declining trend in the global burden of MS by 2035. The incidence rate is expected to be 1.54 per 100,000, with a mortality rate of 0.11 per 100,000 and a DALY rate of 14.59 per 100,000.
Conclusion
The period from 1990 to 2021 has witnessed significant shifts in the global landscape of MS. While the overall burden has grown, advancements in medical care have led to earlier diagnoses, longer survival, and better disease management. The disease’s reach has extended into regions previously thought to be unaffected, underscoring MS as a global health concern.
Limitations
This study’s limitations include variations in reporting standards, diagnostic definitions, and methodologies across different regions. Data availability in under-resourced areas is also a concern, potentially distorting the representation of the actual disease burden.
Future Directions
Targeted strategies tailored to high-risk demographics and regions are crucial to further alleviate the global burden of MS. Continued investment in neurology infrastructure and innovative care models is essential to address the growing MS patient population.
🔗 **Fuente:** https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2025.1616245/full