title: Epidemiology of migraine headache in Santiago, Chile: a prevalence study.
abstract: OBJECTIVE
  To describe the importance of migraine in Santiago, Chile, by analyzing its prevalence, clinical features and impact by age, gender and socioeconomic status.
  
  
  METHODS
  In 1993, a representative sample of 1,540 adults of the province of Santiago were interviewed using a standard questionnaire. A total of 1,385 (89.9%) subjects responded to the survey. Initially, a designated member of each household responded to the questionnaire. Subsequently, each household member with headaches was asked to respond to questions about severity, frequency, location, duration, associated symptoms and impact in work and social activities of their most frequent headaches. Migraine diagnoses were determined in accordance with the International Headache Society (IHS) criteria of 1988.
  
  
  RESULTS
  Recurrent headaches in the past year were found in 516 (36.82%) respondents, 145 (28.1%) males and 371 (71.9%) females. Total prevalence of migraine was found to be 7.3% (95% CI 5.9-8.6); 11.9% (95% CI 9.6-14.2) in females and 2.0% (95% CI 0.9-3.0) in males. Overall, migraine constituted 19.6% (101/516) of all headaches reported in this sample. The prevalence did not vary significantly by age groups or socioeconomic status (SES). Migraine with aura had an overall prevalence of 3.5% (CI 0.8-7.1), and was significantly more frequent in females. In 60-70% of cases the attacks lasted 2-6 h and the frequency was 3.3 and 3.4 per month in females and males respectively. Both males and females reported significantly high percentages of attacks during work.
  
  
  CONCLUSIONS
  Migraine prevalence in a sample of adults of Santiago is similar to that reported in previous studies using IHS criteria. Women of all socioeconomic levels are at an increased risk.
authors.affiliation: Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205, USA. plavados@welchlink.welch.jhu.edu
authors.forename: P M
authors.initials: PM
authors.lastname: Lavados
authors.forename: E
authors.initials: E
authors.lastname: Tenhamm
mesh_terms: D000293:Adolescent; D000328:Adult; D002677:Chile / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology*; D012923:Social Class; D011795:Surveys and Questionnaires