[Prevalence and factors associated to migraine in adult population, Southern Brazil].

OBJECTIVE Migraine is a disease of high prevalence with important impact on people's daily activities. The study aimed at assessing the distribution of migraine in adult population and some of its determinants. METHODS A cross-sectional population-based study was conducted with a multi-stage and probabilistic sampling. A total of 2,715 individuals aged 20 to 64 years old living in the urban area of the city of Pelotas, Southern Brazil, were interviewed. A questionnaire was applied according to the recommendations of the International Headache Society to define the main outcome. Crude and adjusted analysis were performed using Poisson regression. RESULTS The prevalence of headache and migraine was 71.3% (95% CI: 69.6-73.0) and 10.7% (95% CI: 9.4-12.1) respectively. Women showed a four-fold risk greater than men and white skin people showed 1.4 times greater risk than those non-white. Women taking oral contraceptives or shots against pregnancy showed a risk for migraine 1.3 times greater than those women not taking these medicines. Socioeconomic level and regular menstrual periods in the last three months were not found to be associated with migraine. CONCLUSIONS Migraine is a disease that affects mainly women being associated to the white skin color and use of hormonal contraceptives.