Incidence of medically recognized migraine: A 1989-1990 study in Olmsted County, Minnesota

Objective.-To investigate the incidence of medically recognized migraine in Olmsted County, Minnesota, during the years 1989 to 1990. Methods.-We used the records-linkage system of the Rochester Epidemiology Project to identify all subjects who sought medical attention for their headache and had their initial visit for migraine within the study period. Incident cases were classified using specified criteria. Results.-From 9837 records screened, we found 713 incident cases. The average annual incidence rate (new cases per 100 000 person-years) was 343.0 in both sexes combined, 481.6 in women, and 194.4 in men. In women, incidence rates were low at the extremes of age and higher among those aged between 10 and 49 years, with a striking peak at the age of 20 to 29 years. Migraine without aura was the most common type of migraine in women. Men had a more constant risk of migraine throughout life with a lesser peak at the age of 10 to 19 years, and they were equally affected by all types of migraine. Women had consistently higher incidence rates than men at all ages, and there were strikingly higher incidence rates of migraine without aura in women than in men. Conclusions.-Although our incidence rates were restricted to medically recognized cases of migraine, we confirmed previously reported epidemiological patterns.