The rate of multiple sclerosis cases varies greatly by race and ethnicity. A new study suggests the prevalence of MS in Black and white people is similarly high, while much lower in Hispanic and Asian people. 

The study by researchers at Kaiser Permanente Southern California, in Los Angeles, looked at more than 2.6 million adults residing in Southern California. Researchers analyzed Kaiser Permanente health records to determine how many people had a confirmed diagnosis of MS in 2010. Researchers identified 3,863 people with MS. The average age was 52 and 77 percent were women.

Researchers found that MS prevalence per 100,000 people was similarly high for Black and white people, occurring in 226 per 100,000 Black people and in 238 per 100,000 white people. MS prevalence was lower among Hispanic and Asian people, occurring in 70 per 100,000 Hispanic people and 23 per 100,000 Asian people.

The percentage of women with MS was more pronounced among Black and Asian people. Of Black people with MS, 82 percent were women and of Asian people, 84 percent were women. Of white people with MS, 76 percent were women and of Hispanic people, 75 percent were women.

The researchers said more studies are needed to determine whether MS is also an emerging disease among Hispanic people in the U.S. and whether MS susceptibility and prevalence vary among Hispanic or Asian individuals from different cultures and ancestral backgrounds. Larger studies are also needed that look at bigger populations across the U.S.

The research was published in the journal Neurology.