title: The prevalence of multiple sclerosis in the Leeds Health Authority.
abstract: OBJECTIVE
  To determine the prevalence of multiple sclerosis in the Leeds Health District.
  
  
  METHODS
  Multiple sources of case ascertainment were used-namely, neurology departments, hospital episode statistics, general practitioners, the Leeds branch of the Multiple Sclerosis Society, the West Yorkshire Multiple Sclerosis Therapy Centre, community physiotherapists and occupational therapists, the Leeds Wheelchair Centre, and the Young Disabled Unit. Data collection was from retrospective analysis of hospital and primary care case records. A population based incidence register was established by prospectively registering all new patients with diagnoses of multiple sclerosis.
  
  
  RESULTS
  On prevalence day, 30 April 1996, 712 people with multiple sclerosis were identified living in Leeds (population 732,061), giving a prevalence of 97/10(5). The prevalence for definite and probable multiple sclerosis was 84/10(5), and for suspected multiple sclerosis it was 13/10(5). The sex ratio of prevalent people with multiple sclerosis was 2.79 to 1 women to men. The mean age of prevalent cases was 51 years, the mean age at symptom onset was 34 years, and the mean duration of disease was 16 years. Forty cases were prospectively reported as incident cases from 1 November 1995 to 1 February 1996.
  
  
  CONCLUSIONS
  The prevalence of multiple sclerosis in Leeds was found to be similar to that in the south of the United Kingdom but lower than that in Scotland. There is no evidence of a latitudinal gradient of increasing prevalence of multiple sclerosis from the south to the north of England.
authors.affiliation: Department of Neurology, St Jame's University Hospital, Leeds, UK.
authors.forename: H L
authors.initials: HL
authors.lastname: Ford
authors.forename: E
authors.initials: E
authors.lastname: Gerry
authors.forename: C M
authors.initials: CM
authors.lastname: Airey
authors.forename: A
authors.initials: A
authors.lastname: Vail
authors.forename: M H
authors.initials: MH
authors.lastname: Johnson
authors.forename: D R
authors.initials: DR
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D019371:Topography, Medical