The prevalence and characteristics of migraine in a population-based cohort - The GEM Study

Objective: To describe the distribution of migraine and its subtypes in the general population. Background: Previous population-based studies are limi ted by small samples or a narrow age range, do not provide prevalence estim ates of migraine with and without aura, or underestimate prevalence by not accounting for patients missed as a result of using imperfect screening ins truments. Methods: The participants in the Genetic Epidemiology of Migraine Study were comprised of 6,491 adults, age 20 to 65 years, selected randoml y from two county population registries in the Netherlands to participate i n a general health survey (52.7% response). Migraineurs were identified as follows: All participants were screened on headache history. Those meeting screen-positive criteria were given a detailed questionnaire on headache. A total of 1,292 randomly selected screen-positives (83% of screen-positives ) and 197 randomly selected screen-negatives (5% of screen-negatives) were administered a semistructured clinical interview by telephone. Final diagno sis met 1988 International Headache Society criteria. Prevalence of migrain e was estimated for sex and 5-year age strata. Results: The lifetime preval ence of migraine in women was 33% and the 1-year prevalence of migraine in women was 25%. In men, the lifetime prevalence was 13.3% and the 1-year pre valence was 7.5%. Among patients with migraine in the past year, 63.9% had migraine without aura, 17.9% had migraine with aura, and 13.1% had migraine both with and without aura. The prevalence of migraine was significantly h igher in women and not associated with socioeconomic status. Migraineurs su ffered a median of 12 migraine attacks per year; 25% had at least two attac ks per month. Conclusions: The prevalence of migraine is higher then previo usly reported. The coexistence of migraine with and without aura occurs fre quently and has implications for future studies on the genetics of migraine .