Prevalence and burden of chronic migraine in adolescents: results of the chronic daily headache in adolescents study (C-dAS).

OBJECTIVE: To estimate the prevalence of chronic migraine (CM) among adolescents and to describe the epidemiologic profile, headache characteristics, disability, and healthcare utilization of adolescents with CM in the USA. BACKGROUND: Chronic daily headache (CDH) and CM occur in children and adolescents, but are poorly understood in these populations because their presentation is different from that in adults. It may be difficult to assign a definitive diagnosis to young people suffering from CDH because symptoms may fail to meet the criteria for one of the CDH subtypes. METHODS: A large sample of households with at least one resident aged 12 to 19 years was selected in balance with the US Census. Data were collected in 3 phases: (1) mailed questionnaire; (2) telephone interview; and (3) 30-day interactive voice response system diary. CM prevalence was estimated by adapting the second edition of the International Classification of Headache Disorders criteria for CM to include pediatric migraine diagnostic criteria. The population was stratified for medication overuse. Medication overuse was defined as 15 or more days per month of acute medication use. Included in the study were measures of headache characteristics, headache impact (Headache Impact Test), disability (Pediatric Migraine Disability Assessment), and healthcare and medication use. Data are reported on subjects 12 to 17 years of age only. RESULTS: The US adolescent (12-17 years) prevalence rate for CM was 0.79% (0.00-1.70) excluding those with medication overuse and 1.75% (0.62-2.89) when adolescents with medication overuse were included. The majority of adolescents with CM had Headache Impact Test scores greater than or equal to 60, indicating severe headache impact, and mean Pediatric Migraine Disability Assessment scores greater than 17, indicating severe headache and disability. The majority of adolescents with CM (approximately 60%) had not visited a healthcare provider in the previous year and less than one in 5 reported taking medications to prevent headaches during the last month. CONCLUSIONS: Results suggest that CM occurs less frequently in adolescents than adults, but like adults, adolescents are severely burdened by the disorder. Data support an unmet medical need; however, the development of optimal criteria for diagnosing adolescents with CM is critical to fully understanding how medical needs can be met within this complex population.