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MS Prevalence

Worldwide prevalence

Worldwide, MS organizations have estimated that 2.3 million individuals are living with MS.

Improving reporting

You can help improve the accuracy of MS prevalence reporting by joining the Society in our collective efforts to advocate for the establishment of a national registry that would track MS prevalence in the US by joining the Society’s activist network.


Estimating the prevalence of MS

At the present time, MS incidence and prevalence is not consistently reported and tracked in the U.S. as there is no government requirement to do so. In the absence of formally reported data, the Society must rely on either statistically-based estimates, or invest in research studies to better assess the prevalence of MS in the U.S.

The current estimate of MS prevalence in the United States was determined through a National MS Society effort in 2002. The resulting figure of 400,000 individuals estimated to have MS was calculated by applying age-specific rates to various age subgroups on Census 2000 data. This estimate has increased from the initial 123,000 reported in the early nineteen-eighties. While imperfect, it has served as the best estimate of MS prevalence in the U.S. for the past decade, and one with a reasonable scientific basis.

What the National MS Society is doing to improve reporting

Although the Society continues to advocate for the establishment of a national registry that will track the number of people living with MS, we have made a commitment to re-evaluate the current prevalence estimate and investigate the process by which an updated estimate can be identified. Identification of collaborators and necessary resources is currently underway, but will require time and patience.

In the meantime, the Society will continue to report the worldwide prevalence of MS as an estimated 2.3 million individuals, a figure established by international MS organizations. Additionally, the Society will minimize proactive publication of the current 400,000 U.S. prevalence estimate in preparation for a potential new figure in the future.
Prevalence refers to the number of people with a diagnosis of MS

Incidence refers to the number of people newly diagnosed with MS within a given period of time