Population-Based Estimates for the Prevalence of Multiple Sclerosis in the United States by Race, Ethnicity, Age, Sex, and Geographic Region

Abstract

Importance: Racial, ethnic, and geographic differences in multiple sclerosis (MS) are important factors to assess when determining the disease burden and allocating health care resources. Objective: To calculate the US prevalence of MS in Hispanic, non-Hispanic Black (hereafter referred to as Black), and non-Hispanic White individuals (hereafter referred to as White) stratified by age, sex, and region. Design, Setting, and Participants: A validated algorithm was applied to private, military, and public (Medicaid and Medicare) administrative health claims data sets to identify adult cases of MS between 2008 and 2010. Data analysis took place between 2019 and 2022. The 3-year cumulative prevalence overall was determined in each data set and stratified by age, sex, race, ethnicity, and geography. The insurance pools included 96 million persons from 2008 to 2010. Insurance and stratum-specific estimates were applied to the 2010 US Census data and the findings combined to calculate the 2010 prevalence of MS cumulated over 10 years. No exclusions were made if a person met the algorithm criteria. Main Outcomes and Measurements: Prevalence of MS per 100000 US adults stratified by demographic group and geography. The 95% CIs were approximated using a binomial distribution. Results: A total of 744781 persons 18 years and older were identified with MS with 564426 cases (76%) in females and 180355 (24%) in males. The median age group was 45 to 54 years, which included 229216 individuals (31%), with 101271 aged 18 to 24 years (14%), 158997 aged 35 to 44 years (21%), 186758 aged 55 to 64 years (25%), and 68539 individuals (9%) who were 65 years or older. White individuals were the largest group, comprising 577725 cases (77%), with 80276 Black individuals (10%), 53456 Hispanic individuals (7%), and 33324 individuals (4%) in the non-Hispanic other category. The estimated 2010 prevalence of MS per 100000 US adults cumulated over 10 years was 161.2 (95% CI, 159.8-162.5) for Hispanic individuals (regardless of race), 298.4 (95% CI, 296.4-300.5) for Black individuals, 374.8 (95% CI, 373.8-375.8) for White individuals, and 197.7 (95% CI, 195.6-199.9) for individuals from non-Hispanic other racial and ethnic groups. During the same time period, the female to male ratio was 2.9 overall. Age stratification in each of the racial and ethnic groups revealed the highest prevalence of MS in the 45- to 64-year-old age group, regardless of racial and ethnic classification. With each degree of latitude, MS prevalence increased by 16.3 cases per 100000 (95% CI, 12.7-19.8; P