title: Outcomes and predictors of chronic daily headache in adolescents: a 2-year longitudinal study.
abstract: OBJECTIVE
  To assess the outcomes and predictors of chronic daily headache (CDH) in a community-based cohort of adolescents.
  
  
  METHODS
  We established a field sample of 122 adolescents (32 M/90 F, ages 12 to 14) with CDH in 2000. These adolescents received annual follow-up by neurologists for 2 years via a semistructured telephone interview. CDH was defined as > or =15 headache days/month, average > or =2 h/day for >3 months; subtypes were classified based on the original and appendix criteria of the International Classification of Headache Disorders (2nd ed.; ICHD-2). Poor outcome was defined as persistence of CDH at 2 years.
  
  
  RESULTS
  Follow-up response rates were 92% in 2001 and 84% in 2002. Average monthly headache frequency was 11.0 +/- 9.7 days in 2001 and 7.7 +/- 6.5 days in 2002. CDH persistence rates were 40% in 2001 and 25% in 2002. Medication overuse declined from 20% (baseline) to 6% at 2 years. The prevalence of migraine did not change throughout the follow-up (67 to 60%), whereas that of tension-type headache deceased from 86 to 46% (p < 0.001). Chronic migraine prevalence increased markedly at baseline and became the most common CDH subtype at follow-up when using the ICHD-2 appendix criteria. During follow-up, seven subjects (6%) dropped out of school. Independent predictors for CDH persistence were medication overuse and major depression.
  
  
  CONCLUSIONS
  Most adolescents with chronic daily headache (CDH) continued to have frequent headaches, although the incidence of CDH declined at follow-up. Migraine diagnosis gained prominence as headache frequency decreased. The percentages of chronic migraine in adolescents with CDH increased obviously if the appendix criteria were applied.
authors.affiliation: Department of Neurology, National Yang-Ming University School of Medicine, Taiwan. sjwang@vghtpe.gov.tw
authors.forename: Shuu-Jiun
authors.initials: SJ
authors.lastname: Wang
authors.forename: Jong-Ling
authors.initials: JL
authors.lastname: Fuh
authors.forename: Shiang-Ru
authors.initials: SR
authors.lastname: Lu
authors.forename: Kai-Dih
authors.initials: KD
authors.lastname: Juang
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects; D015984:Causality; D002648:Child; D015331:Cohort Studies; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000453:epidemiology; D005260:Female; D020773:Headache Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008881:Migraine Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care; D010349:Patient Compliance; D015995:Prevalence; D018781:Tension-Type Headache / Q000175:diagnosis / Q000188:drug therapy* / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D000700:Analgesics