Epidemiology of multiple sclerosis in iran: an updated systematic review and meta-analysis.

BACKGROUND

This study aimed to provide an updated estimate of the prevalence and incidence of multiple sclerosis (MS) in Iran.

METHOD: To ensure the methodological rigor of this review, the protocol was developed in accordance with the MOOSE guidelines, and results were reported based on PRISMA statement. Two independent reviewers systematically searched national and international databases using MeSH terms from inception to January 1, 2026, without time restrictions. Data were pooled using Comprehensive Meta-Analysis software version 2, applying a random-effects model. A p-value of <0.05 was considered statistically significant.

RESULTS

A total of 56 articles comprising 142 individual studies were included in meta-analysis. The overall prevalence of MS in Iran, based on 139 studies, was estimated at 33.7 per 100,000 population (33.7/ 100,000) (95%CI: 30.9-39.0). The prevalence was 23.8/ 100,000 (95%CI: 21.0-27.0) in men and 76.0/ 100,000 (95%CI: 67.5-85.5) in women. Based on 80 studies, the incidence of MS in Iran was estimated at 4.2/ 100,000 (95%CI: 2.7-6.6), with an incidence of 2.2/ 100,000 (95%CI: 1.9-2.4) in men and 6.7/100,000 (95%CI: 5.9-7.5) in women. Meta-regression analysis revealed a statistically significant upward trend in both prevalence and incidence of MS in Iran over time (P < 0.001).

CONCLUSIONS

The findings demonstrate that both the prevalence and incidence of MS in Iran are considerable and have significantly increased over time, emphasizing the need for further investigation into context-specific risk factors within the country.