Prevalence of migraine in Iceland.

BACKGROUND: There are few studies assessing the prevalence and characteristics of migraine in the Icelandic population. Previous Icelandic studies have methodological limitations and no study has been performed using full ICHD-3 criteria. METHODS: The study is based on data from a pilot for the SAGA (Stress-And-Gene-Analysis) cohort study conducted in 2014. The participants were women invited to cancer screening and men randomly sampled from the National Registry of Iceland. Participants answered an online health questionnaire including standardized, validated questions, used to identify migraine as defined by the ICHD-3 criteria. Estimates are provided for the one-year period prevalence of migraine overall, and the migraine subgroups migraine with aura, migraine without aura, and probable migraine. RESULTS: Of 1390 individuals invited to participate, 916 responded (65.9%). There were 402 men (44.0%) and 514 women (56.0%), 21 to 75 years of age with a median age of 50 years. The 1-year period prevalence of migraine was 14.4% overall, 19.3% in women and 8.2% in men with a female-to-male ratio of 2.3:1. The prevalence of subjects with migraine without aura (MO) but not migraine with aura (MA) was 6.3%, Conversely, the prevalence of subjects with MA who did not meet the criteria for MO was 4.9%. A total of 3.2% of the participants met the criteria for both migraine with and without aura (MA + MO). The prevalence of probable migraine was 2.6% overall, 2.7% in women and 2.5% in men. CONCLUSIONS: The 1-year prevalence of migraine in Iceland was 14.4% overall, 19.3% in women and 8.2% in men. These rates are in line with European prevalence estimates and are slightly higher than United States estimates. The 1-year prevalence of probable migraine was 2.6%, 2.7% in women and 2.5% in men.