Epidemiology of pediatric multiple sclerosis: A systematic literature review and meta-analysis

Background: Multiple sclerosis (MS) is a debilitating immune disease leading to demyelination, neurodegeneration, and chronic inflammation of the central nervous system. Pediatric MS is a rare form of the disease and effects approximately 2-10% of individuals with MS. Diagnostic criteria and therapies are continuously evolving, thus it is imperative to further understand the epidemiology and subsequently global and regional disease burden of pediatric MS. Our objective was to conduct a systematic literature review and meta-analysis to assess the incidence and prevalence of pediatric MS globally. Subgroup analyses were also conducted by region and diagnostic criteria used to ascertain cases. Methods: A systematic literature review was conducted using searches run in EMBASE and MEDLINE. A hand search was also conducted, and the bibliographies of any relevant articles were reviewed for any studies potentially not captured by the databases. A random effects model was used to combine epidemiological estimates across studies. Subgroup analyses by region and diagnostic criteria were performed in instances when three or more studies were available for analyses. Results: A total of 2,965 publications were identified, of which 187 were eligible for full-text screening. A total of 21 full-text articles met the eligibility criteria and were included for data extraction, with 18 studies included for meta-analysis. Regional epidemiologic estimates were obtained for North America, Europe, Middle East, and Asia. Country specific data was available for Canada, United States, Germany, Iceland, Netherlands, Sardinia, Slovenia, UAE/Abu Dhabi, Iran, Israel, Jordan, Kuwait, Tunisia, Taiwan, and Japan. Thirteen studies representing 12 countries reported incidence of pediatric MS. Overall incidence ranged from 0.05 to 2.85 and pooled global incidence was calculated to be 0.87 (95% CI: 0.35-1.40) per 100,000 individuals annually. Ten studies representing 10 countries reported on the prevalence of pediatric MS. Overall prevalence ranged from 0.69 to 26.92 per 100,000 individuals and pooled global prevalence was calculated to be 8.11 (95% CI: 2.28-13.93) per 100,000 people. Conclusion: To our knowledge, this is the first meta-analysis conducted to provide pooled estimates of incidence and prevalence estimates of pediatric MS globally. In general, incidence estimates were similar across regions; however, prevalence was found to be more variable. Noticeable gaps in evidence include a lack of pediatric MS estimates from other large regions of the world such as Africa, South America, Russia, and Australia. Moreover, there is a need for more population-based studies using the most up to date diagnostic criteria.