title: Chronic daily headache with analgesic overuse: epidemiology and impact on quality of life.
abstract: OBJECTIVE
  To analyze the prevalence and demography of chronic daily headache (CDH) with analgesic overuse.
  
  
  METHODS
  A population of 9,984 inhabitants aged 14 or older living in Santoña, Spain, was studied. The authors personally interviewed 4,855 subjects, using a quota sampling approach. Those with headache for > or = 10 days/month and some analgesic use were asked to fill in a diary over the course of 1 month. Then, subjects were classified into CDH with or without analgesic overuse subtypes. Quality of life (Short Form-36 Health Survey [SF-36]) was also assessed in this second interview.
  
  
  RESULTS
  Headache for > or = 10 days/month with analgesic consumption was reported by 332 subjects. Seven had secondary headache. Seventy-four (standardized prevalence 1.41%, 95% CI 1.1 to 1.8) fulfilled criteria for CDH with analgesic overuse. Prevalence in women (2.6%, 2.0 to 3.3) was much higher than in men (0.19%, 0.006 to 0.52). Mean age was 56 years (range 19 to 82 years). As recalled by the subjects, the mean age at onset of CDH was 38 years (range 9 to 82 years), whereas the mean age at onset of CDH with frequent analgesic consumption was 45 years (range 19 to 80 years) and that of primary headache was 22 years (range 5 to 60 years). CDH subjects showed a significant decrease in each SF-36 health-related score as compared with healthy control subjects. Transformed migraine was diagnosed in 49 (prevalence 0.9%), chronic tension-type headache in 20 (0.4%), and new daily persistent headache in 5 (0.1%). Thirty-five percent of patients overused simple analgesics, 22% ergotics, 12.5% opioids, and 2.7% triptans; the remaining 27.8% were overusing different combinations.
  
  
  CONCLUSIONS
  CDH with analgesic overuse is a common disorder in the general population, mainly in women in their fifties, in whom 5% meet its diagnostic criteria.
authors.affiliation: Health Center of Santoña, University Hospital Marqués de Valdecilla (UC), Cantabria, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Colás
authors.forename: P
authors.initials: P
authors.lastname: Muñoz
authors.forename: R
authors.initials: R
authors.lastname: Temprano
authors.forename: C
authors.initials: C
authors.lastname: Gómez
authors.forename: J
authors.initials: J
authors.lastname: Pascual
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics / Q000009:adverse effects*; D002908:Chronic Disease; D005260:Female; D020773:Headache Disorders / Q000139:chemically induced* / Q000145:classification / Q000453:epidemiology*; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D011788:Quality of Life; D017678:Sex Distribution; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D000700:Analgesics