Background: The aim of this study was to provide the prevalence and sex-ratio of subtypes of migraine diagnosed by neurological interview according to the criteria of the International Headache Society.
Methods: In all, 3000 males and 1000 females aged 40 years were randomly selected from the Danish population. They received a mailed questionnaire regarding migraine. The questionnaire response rate was 87%. People with self-reported migraine and a random sample of those reporting no migraine were invited to a headache interview, and a physical and a neurological examination. Those not reacting to the invitation were interviewed by telephone. Participation at the interview was 87%. Kappa was 0.77 validating self-reported migraine in the questionnaire against the diagnosis of the clinical interview.
Results: Lifetime prevalences of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were 8%, 4%, 1% and 1% in males and 16%, 7%, 3% and 2% in females. Overall lifetime prevalence of any type of migraine was 18%; 12% in males and 24% in females. This is lower than the sum of the prevalences since migraine diagnoses are not mutually exclusive. The male:female ratios of migraine without aura, migraine with aura, migraine aura without headache, and migrainous disorder were approximately 1:2.
Conclusions: Migraine is more prevalent than previously thought. There was a significant preponderance in females of all the subtypes of migraine except migrainous disorder.