- A study by leading experts estimates that in 2017, nearly 1 million adults (up to 913,925) were living with MS in the United States. This is more than twice the previously reported number from a national study in 1975 and subsequent updates.
- The study was launched and supported by the National MS Society with the goal of determining the best way to develop a scientifically sound and economically feasible estimate of the number of people in the U.S. who have MS.
- Having an updated prevalence estimate will allow a better understanding of the needs of people with MS and the economic burdens imposed by the disease on families and society. It will be a starting point for researchers to understand if MS is increasing, or if there are MS geographic clusters that may hold clues to new risk factors that trigger MS. These data will also help ensure that the National MS Society is able to connect to and support all people affected by MS.
- The team published its findings in three papers early online on February 15, 2019 in the journal Neurology (follow links below).
“This study tells us many things, but one thing in particular -- twice as many people need a cure,” said Cyndi Zagieboylo, President and CEO of the National Multiple Sclerosis Society. “We must do more. We need to raise more money to fund more research; we need to fund the programs and services that help people with MS live their best lives; and we need to make sure the voices of people living with MS are heard and their rights to have quality, affordable health care are protected.”
In the United States, there has not been a scientifically sound, national study of prevalence since 1975. Additionally, MS incidence (the number of people newly diagnosed with MS within a given period of time) and prevalence (the number of people living with a diagnosis of MS within a given period of time) are not consistently reported or tracked in the U.S., and there is no government requirement to do so.
The National MS Society has been advocating for a national neurological disease surveillance system that would provide deeper information about the prevalence and impacts of MS and other disorders. In 2016, Congress finally passed the 21st Century Cures Act, which authorized the creation of the National Neurological Conditions Surveillance System. In 2018, funding was provided for its implementation by the Centers for Disease Control and Prevention
In the meantime, to address the gap in prevalence estimates, the National MS Society launched the MS Prevalence Initiative in 2014 with the goal of determining the best way to develop a scientifically sound and economically feasible estimate of the number of people in the U.S. who have MS (Nelson and co-authors
). This initiative included leading experts in MS epidemiology, statistics and healthcare, who utilized administrative datasets from a variety of sources including Medicare, Medicaid, Veteran’s Health Administration, and three large private health insurers.
An international team of epidemiologists and other experts led by Mitchell Wallin, MD, MPH (Department of Veterans Affairs MS Center of Excellence and Georgetown University School of Medicine) and Nicholas LaRocca, PhD (Vice President, Health Care Delivery and Policy Research, National MS Society) developed and tested a method of detecting adults with MS (Culpepper and co-authors
), based on health claims data from private and public insurers and the sophisticated application of statistical calculations.
The team developed and tested an MS case-finding “algorithm” – in other words, a step-by-step procedure for accurately identifying MS cases in health insurance datasets and calculating prevalence. The team notes that this method has the potential to be used for other chronic neurologic conditions that could serve as a starting point for the National Neurological Conditions Surveillance System
In addition, methods were developed to adjust for cases not counted in particular health claims datasets, as well as for people without insurance and people who may not have seen their doctors during the 3-year (2008 to 2010) span of the claims that were examined. They used population data to develop estimates of the prevalence of MS in the U.S. in 2010, and then applied a calculation of prevalence growth rate (observed in claims data) to estimate the national MS prevalence for 2017.
The findings were published early online in the journal Neurology
(Wallin and co-authors
) on February 15, 2019. The estimated prevalence of MS in the U.S. in 2010 was 309 cases per 100,000 people in the population, or 727,344 adults with MS. The updated 2017 number was estimated to be up to 363 cases per 100,000, or 913,925
adults with MS. This is more than twice the previously reported number derived from a national study in 1975 and subsequent updates.
Nearly 1 million people are living with MS in the U.S. -- more than twice the previous estimate. Having this scientifically sound prevalence estimate by leading experts will allow a better understanding of the needs of people with MS and the economic burdens imposed by the disease on families and society. It will be a starting point for researchers to understand if MS is increasing, or if there are MS geographic clusters that hold clues to factors that trigger MS. These data will also help ensure that the National MS Society is able to connect to and support all people affected by MS.
The National MS Society continues to support the CDC’s launch of the National Neurological Conditions Surveillance System. Beyond a basic prevalence count, this system could provide additional information to help researchers refine and target research questions, including:
Read the open-access papers published in Neurology
FAQs and other information about the prevalence of MS
- Geographic clusters, which may provide clues to the cause of MS and other disorders;
- Demographic and genetic information (age, sex, race); and
- Health care practices and utilization.