Probable migraine in the United States : results of the American Migraine Prevalence and Prevention (AMPP) Study

Probable migraine (PM) is a prevalent migraine subtype fulfilling all but one criterion for migraine with or without aura. The aims of this study were: (i) to describe the epidemiology, medical recognition and patterns of treatment for PM in the USA; (ii) to compare the patterns of preventive PM treatment in the population with expert panel guidelines for preventive treatment. A validated self-administered headache questionnaire was mailed to a random sample of 120 000 US households. Subjects were classified as PM according to the second edition of the International Classification of Headache Disorders (ICHD-2). The questionnaire also assessed patterns of migraine treatment. Guidelines for preventive medication use were developed by a panel of headache experts, who used headache frequency and impairment to assess the need for preventive therapy and the gap between current and ideal use. Our sample consisted of 162 576 individuals aged ≥12 years. The 1-year period prevalence of PM was 4.5% (3.9% in men and...