A team of researchers funded by the National Multiple Sclerosis Society analyzed information from health insurance claims to estimate the prevalence of MS in the U.S., which includes data for each state. The team also estimated the prevalence of how many people of different races and ethnicities live with MS.
This new information confirms that anyone can develop MS. It will inform advocacy efforts that focus on increasing access and resources for MS care. It may also offer clues to factors that contribute
to why people get MS. The study has now been published in JAMA Neurology
and can be read by anyone without the need for a paid subscription.
“This study makes it very clear that anyone can get MS, and it’s critical that healthcare providers are aware of that so anyone, regardless of age, race, ethnicity or sex assigned at birth can be diagnosed and treated without delay,” said Cyndi Zagieboylo, President and CEO of the National MS Society. “This study also provides important information that will help identify gaps in MS care and help scientists identify factors that may play a role in susceptibility.”
In 2019, a National MS Society-funded Multiple Sclerosis Prevalence Workgroup estimated the prevalence of MS in the U.S. to be nearly 1 million people
, twice as many as previous estimates. Some of the same team members and others have been continuing research to provide more details about who has MS in the U.S. The team was led by Mitchell Wallin, MD, MPH (VA MS Center of Excellence and University of Maryland School of Medicine) and Lorene Nelson, PhD, MS (Stanford University School of Medicine).
The team evaluated three years’ worth of health insurance claims of 96 million adults covered by military, public and private insurers to locate adults living with multiple sclerosis. (Individuals’ actual identities remained private.)
Why This Study Matters:
- Using the methods they developed for the 2019 study, the team estimated in more detail how many individuals who are age 18 or older are living with MS in various states.
- To the extent possible, they also estimated MS prevalence among people of different races or ethnicities living in specific regions.
Early diagnosis and treatment are critical to minimizing progression in MS, which is why it’s important to increase public understanding that MS is a disease that can affect anyone, regardless of race or locale. This study helps to confirm the profound impact structural racism, healthcare inequities and lack of representation in clinical research have had in driving misconceptions about the prevalence of MS on historically underserved and underrepresented populations.
Important to Know:
- There is strong evidence that there is a higher prevalence of MS in northern regions of the U.S. compared to southern regions. However, the team noted that more research is needed to determine all of the factors that may contribute to this geographic variation.
- Overall, in the U.S., there is a higher prevalence of MS in white people, followed by Black people, “other races,” and then people with Hispanic/Latinx ethnicity.
- The prevalence rates were reported as the number of people that have MS out of 100,000 people in the general population in the U.S.:
- White people (but not Latinx/Hispanic): 374.8 per 100,000 (about 4 people out of 1,000)
- Black people (but not Hispanic/Latinx): 298.4 per 100,000 (about 3 people out of 1,000)
- People of “other races” (including Asians, Native Americans, Alaska natives, multi-race individuals and unknown): 197.7 per 100,000 (about 2 people out of 1,000)
- Hispanic/Latinx people (of any race): 161.2 per 100,000 (about 1 ½ people out of 1,000)
Is MS Increasing?
- Numbers: In the 2019 study, the team estimated the prevalence of MS in the U.S. to be 727,344 people in 2010. Then they applied statistical methods to project the updated 2019 prevalence estimate of nearly 1 million people living with MS in the U.S. For this study, they used the 2010 figure to estimate prevalence rates by location. Further work by the Centers for Disease Control and Prevention (CDC) may provide updates based on the latest 2020 Census population count.
- Missing Data on Race and Ethnicity: Some of the health insurance claims data did not indicate the race or ethnicity of individuals, so projections were used. For this reason, the team was unable to estimate separate prevalence for people of Asian backgrounds. People of Asian backgrounds were categorized as “other” ethnicity or race. (The team was also not able to include children, people who use the Indian (Native American) Health Service, people in prison, or undocumented residents.)
- Prevalence vs. Incidence: This paper reports on the prevalence of MS in the U.S. and in people according to race and ethnicity. Prevalence is the number of people living with a diagnosis of MS at a particular point in time, in a particular place.
- This study did not estimate the incidence of MS, which is the number of people newly diagnosed with MS within a given period of time. Some studies (such as this one) have suggested that Black people have a higher incidence of being diagnosed with MS compared to white people.
- Gender: Until recently, gender identity and sexual orientation were not captured in census questionnaires or in health insurance claims. For this reason, the team did not have access to gender identity as part of this study.
Based on this study, it is not yet possible to understand if MS is increasing. The authors speculate that higher numbers of people with MS than previously reported may relate to people living longer, improved MS diagnosis and possibly to people of underrepresented populations being diagnosed at higher rates.
The National MS Society continues to support the CDC’s National Neurological Conditions Surveillance System. MS was one of the two conditions used to pilot the system. This system will produce actionable and timely information to increase the understanding of neurological conditions, including MS, and catalyze research into causes, diagnosis, and treatment.
"The prevalence of MS in the United States: Population-based estimates by race, ethnicity, age, sex, and geographic region,"
by Michael Hittle, William J. Culpepper, Annette Langer-Gould, Ruth Ann Marrie, Gary R. Cutter, Wendy E. Kaye, Laurie Wagner, Barbara Topol, Nicholas G. LaRocca, Lorene M. Nelson, Mitchell T. Wallin, was published online in JAMA Neurology on May 15, 2023.
Read more about who gets MS