title: The prevalence of multiple sclerosis in 3 US communities.
abstract: BACKGROUND
  We estimated the prevalence of multiple sclerosis (MS) in 3 large geographic areas in the southern, middle, and northern United States.
  
  
  METHODS
  The primary data source was medical records from office visits to private neurologists' practices or to neurology departments in tertiary care facilities during a 3-year period. Additional data sources included patient advocacy groups, nursing homes, and general practitioners.
  
  
  RESULTS
  Three-year US age-adjusted prevalence estimates for the study areas varied substantially. The prevalence was lowest (47.2 per 100,000 population) in the Texas study area (33 degrees 30' north latitude), intermediate (86.3 per 100,000 population) in the Missouri study area (39 degrees 07' north latitude), and highest (109.5 per 100,000 population) in the Ohio study area (41 degrees 24' north latitude). The geographic differences remained strong after age-adjustment to the world standard population. The inverse association between UV light exposure and MS prevalence estimates was consistent with this observed latitude gradient. In all 3 areas, MS prevalence was highest among women, people aged 40 to 59 years, and non-Hispanics.
  
  
  CONCLUSIONS
  These results provide necessary prevalence estimates for community cluster investigations and establish baseline estimates for future studies to evaluate temporal trends in disease prevalence.
authors.affiliation: Agency for Toxic Substances and Disease Registry, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors.forename: Curtis W
authors.initials: CW
authors.lastname: Noonan
authors.forename: Dhelia M
authors.initials: DM
authors.lastname: Williamson
authors.forename: Judy P
authors.initials: JP
authors.lastname: Henry
authors.forename: Robert
authors.initials: R
authors.lastname: Indian
authors.forename: Sharon G
authors.initials: SG
authors.lastname: Lynch
authors.forename: John S
authors.initials: JS
authors.lastname: Neuberger
authors.forename: Randolph
authors.initials: R
authors.lastname: Schiffer
authors.forename: Janine
authors.initials: J
authors.lastname: Trottier
authors.forename: Laurie
authors.initials: L
authors.lastname: Wagner
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology*; D015995:Prevalence; D044469:Racial Groups; D014481:United States / Q000453:epidemiology