PREVALENCE OF MIGRAINE HEADACHE AND ASSOCIATION WITH SEX, AGE, RACE, AND RURAL-URBAN RESIDENCE - A POPULATION-BASED STUDY OF GEORGIA MEDICAID RECIPIENTS

The estimates of migraine headache prevalence vary widely and fluctuat e with the population examined and the methodologic factors used in st udies examining this condition. As an alternative to survey techniques , a retrospective review of Medicaid claims data from 22 continuous mo nths (January 1, 1989, to October 31, 1990) was used to detect medical episodes and physician-initiated pharmacologic therapy indicative of migraine headache. Specifically, the objectives of this study were to measure the prevalence of migraine headache in Georgia Medicaid recipi ents, estimate the prevalence in the US population, and describe the r elationships between migraine and sociodemographic variables including sex, age, race, and rural versus urban residence. Logistic regression was used to isolate the independent effects of age, race, residence, and length of Medicaid eligibility on the presence or absence of migra ine. The data consisted of adjudicated claims for 847,453 Georgia Medi caid recipients. Medicaid profiles for 678,079 recipients (468,448 fem ale and 209,631 male) aged older than 4 years were analyzed as persons at risk of migraine. Migraine was identified in 6518 (1.39%) females and 991 (0.47%) males. Adjusting for eligibility, age, and race, the p rojected 22-month period prevalence for the United States was estimate d as 3.83% (females) and 1.33% (males). Females, whites, and individua ls residing in rural counties were more likely to suffer from migraine headache than their respective comparison groups. For both sexes, the peak prevalence was in the fourth and fifth decades of life. Migraine headache in the United States is estimated to afflict 4.5 million fem ales and 1.4 million males. This prevalence is lower than previously r eported and indicates that migraine headache may not be as common as p reviously believed. An alternative explanation is that many Medicaid r ecipients self-treat the condition, thus circumventing physician care and subsequent diagnosis and treatment.