title: The prevalence and characteristics of migraine in a population-based cohort: the GEM study.
abstract: OBJECTIVE
  To describe the distribution of migraine and its subtypes in the general population.
  
  
  BACKGROUND
  Previous population-based studies are limited by small samples or a narrow age range, do not provide prevalence estimates of migraine with and without aura, or underestimate prevalence by not accounting for patients missed as a result of using imperfect screening instruments.
  
  
  METHODS
  The participants in the Genetic Epidemiology of Migraine Study were comprised of 6,491 adults, age 20 to 65 years, selected randomly from two county population registries in the Netherlands to participate in a general health survey (52.7% response). Migraineurs were identified as follows: All participants were screened on headache history. Those meeting screen-positive criteria were given a detailed questionnaire on headache. A total of 1,292 randomly selected screen-positives (83% of screen-positives) and 197 randomly selected screen-negatives (5% of screen-negatives) were administered a semistructured clinical interview by telephone. Final diagnosis met 1988 International Headache Society criteria. Prevalence of migraine was estimated for sex and 5-year age strata.
  
  
  RESULTS
  The lifetime prevalence of migraine in women was 33% and the 1-year prevalence of migraine in women was 25%. In men, the lifetime prevalence was 13.3% and the 1-year prevalence was 7.5%. Among patients with migraine in the past year, 63.9% had migraine without aura, 17.9% had migraine with aura, and 13.1% had migraine both with and without aura. The prevalence of migraine was significantly higher in women and not associated with socioeconomic status. Migraineurs suffered a median of 12 migraine attacks per year; 25% had at least two attacks per month.
  
  
  CONCLUSIONS
  The prevalence of migraine is higher then previously reported. The coexistence of migraine with and without aura occurs frequently and has implications for future studies on the genetics of migraine.
authors.affiliation: Department of Chronic Disease Epidemiology, Leiden University Medical Centre, The Netherlands.
authors.forename: L J
authors.initials: LJ
authors.lastname: Launer
authors.forename: G M
authors.initials: GM
authors.lastname: Terwindt
authors.forename: M D
authors.initials: MD
authors.lastname: Ferrari
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology* / Q000235:genetics*; D009426:Netherlands / Q000453:epidemiology; D010641:Phenotype; D015995:Prevalence; D011795:Surveys and Questionnaires