title: The impact of chronic migraine: The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study methods and baseline results.
abstract: BACKGROUND
  Longitudinal migraine studies have rarely assessed headache frequency and disability variation over a year.
  
  
  METHODS
  The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study is a cross-sectional and longitudinal Internet study designed to characterize the course of episodic migraine (EM) and chronic migraine (CM). Participants were recruited from a Web-panel using quota sampling in an attempt to obtain a sample demographically similar to the US population. Participants who passed the screener were assessed every three months with the Core (baseline, six, and 12 months) and Snapshot (months three and nine) modules, which assessed headache frequency, headache-related disability, treatments, and treatment satisfaction. The Core also assessed resource use, health-related quality of life, and other features. One-time cross-sectional modules measured family burden, barriers to medical care, and comorbidities/endophenotypes.
  
  
  RESULTS
  Of 489,537 invitees, we obtained 58,418 (11.9%) usable returns including 16,789 individuals who met ICHD-3 beta migraine criteria (EM (<15 headache days/mo): n = 15,313 (91.2%); CM (≥ 15 headache days/mo): n = 1476 (8.8%)). At baseline, all qualified respondents (n = 16,789) completed the Screener, Core, and Barriers to Care modules. Subsequent modules showed some attrition (Comorbidities/Endophenotypes, n = 12,810; Family Burden (Proband), n = 13,064; Family Burden (Partner), n = 4022; Family Burden (Child), n = 2140; Snapshot (three months), n = 9741; Core (six months), n = 7517; Snapshot (nine months), n = 6362; Core (12 months), n = 5915). A total of 3513 respondents (21.0%) completed all modules, and 3626 (EM: n = 3303 (21.6%); CM: n = 323 (21.9%)) completed all longitudinal assessments.
  
  
  CONCLUSIONS
  The CaMEO Study provides cross-sectional and longitudinal data that will contribute to our understanding of the course of migraine over one year and quantify variations in headache frequency, headache-related disability, comorbidities, treatments, and familial impact.
authors.affiliation: Allergan Inc., Irvine, CA, USA adams_aubrey@allergan.com.
authors.forename: Aubrey Manack
authors.initials: AM
authors.lastname: Adams
authors.affiliation: Vedanta Research, Chapel Hill, NC, USA Endpoint Outcomes, Boston, MA, USA The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Serrano
authors.affiliation: The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA Montefiore Headache Center, Bronx, NY, USA.
authors.forename: Dawn C
authors.initials: DC
authors.lastname: Buse
authors.affiliation: Vedanta Research, Chapel Hill, NC, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Reed
authors.affiliation: Vedanta Research, Chapel Hill, NC, USA.
authors.forename: Valerie
authors.initials: V
authors.lastname: Marske
authors.affiliation: Vedanta Research, Chapel Hill, NC, USA.
authors.forename: Kristina M
authors.initials: KM
authors.lastname: Fanning
authors.affiliation: The Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, USA Montefiore Headache Center, Bronx, NY, USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Lipton
mesh_terms: D000328:Adult; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders; D018434:Sickness Impact Profile; D016896:Treatment Outcome
keywords: Migraine disorders; chronic migraine; epidemiology; episodic migraine; headache