A new study published In JAMA Neurology looked at the people who have multiple sclerosis (MS) in the United States: their race and ethnicity, age, sex, and where they lived.

Researchers studied the private insurance, Veterans Affairs, Medicaid and Medicare health claims of 96 million people to find adults with MS between 2008 and 2010; the data analysis took place between 2019 and 2022.

The study counted more than 744,000 adults, age 18 or older, who had MS. Researchers said 76 percent of those people with MS were female, and 24 percent were male, with the median age group being 45 to 54 years old.

The authors of “Population-Based Estimates for the Prevalence of Multiple Sclerosis in the United States by Race, Ethnicity, Age, Sex, and Geographic Region” said, “This study found that White individuals had the highest MS prevalence, followed by Black individuals, individuals from other non-Hispanic racial and ethnic groups, and Hispanic individuals. Inconsistent racial and ethnic classifications created heterogeneity within groups. In the United States, MS affects diverse racial and ethnic groups. Prevalence of MS increases significantly and nonuniformly with latitude in the United States, even when adjusted for race, ethnicity, age, and sex. These findings are important for clinicians, researchers, and policy makers.”

Researchers also found a higher prevalence of people with MS living “in the northern latitudes, with the highest estimates occurring in the mountain states. Additional analyses are needed to examine climatological, demographic, infectious, and other factors that may contribute to this geographic variation.”

They concluded that the distribution of MS in the United States “has become more racially and ethnically diverse,” and that MS overall “has become more prevalent and demographically diverse.”