title: Has the prevalence of migraine and tension-type headache changed over a 12-year period? A Danish population survey.
abstract: OBJECTIVE
  The present study aims to compare the prevalence of primary headaches in Denmark in two periods as only few replicate studies have re-evaluated the prevalence of primary headaches.
  
  
  METHODS
  The 2001 study is a replicate of a cross-sectional survey of primary headaches in 1989, and compares 297 subjects aged 25-36 years from the general population, with the 294 comparable subjects invited in 1989. Medical doctors diagnosed all headaches using IHS-classification.
  
  
  RESULTS
  The participation rate was 75% in 1989 and 70% in 2001. The prevalence of migraine did not change significantly (11-15%), while the prevalence of tension-type headache (79-87%), especially of frequent tension-type headache (29-37%) increased significantly. The prevalence of chronic tension-type headache (2-5%) tended to increase. The proportion of the migraineurs with migraine 14 days or more per year increased (12-38%). Female gender was a risk factor for both primary headaches. The majority of migraineurs (92-94%) also reported coexistent tension-type headache.
  
  
  CONCLUSIONS
  The prevalence of tension-type headache but not of migraine increased. The increase in migraine and tension-type headache frequency suggests a higher individual and societal impact of primary headaches now, than 12 years ago.
authors.affiliation: Research Centre for Prevention and Health, Glostrup University Hospital, Glostrup, Denmark. anchly01@glostruphosp.kbhamt.dk
authors.forename: Ann Christine
authors.initials: AC
authors.lastname: Lyngberg
authors.forename: Birthe K
authors.initials: BK
authors.lastname: Rasmussen
authors.forename: Torben
authors.initials: T
authors.lastname: Jørgensen
authors.forename: Rigmor
authors.initials: R
authors.lastname: Jensen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000175:diagnosis / Q000453:epidemiology*; D018781:Tension-Type Headache / Q000175:diagnosis / Q000453:epidemiology*