Burden of migraine related to menses: results from the AMPP study.

Background: Studies of the difference between menstrually associated and non-menstrually associated migraine are somewhat controversial. The majority of studies have focused on comparing menstrual to non-menstrual attacks rather than comparing study groups with different migraine diagnoses with respect to menstruation. As there is limited knowledge available on the overall impact and burden of migraine among groups of women with and without menstrually associated migraine our goal was to examine differences between these groups. We hypothesized that there would be greater burden of migraine related to menstruation and headache frequency in a population study across groups of women.
Methods: We analyzed data from the American Migraine Prevalence and Prevention (AMPP) Study, a longitudinal, US, population-based study. We included female respondents to the 2009 survey, aged 18 to 60, who met modified ICHD-2 criteria for migraine, were actively menstruating and fit one of three definitions based on the self-reported association of menses and migraine attacks: self-reported predominantly menstrual migraine (MM, attacks that only or predominantly occur at the time of menses), self-reported menstrually-associated migraine (MAM, attacks commonly associated with menses, but that also occur at other times of the month), and self-reported menstrually-unrelated migraine (MUM). These three groups were compared on characteristics and measures of headache impact and burden (Headache Impact Test- 6 item (HIT-6) and Migraine Disability Assessment Scale (MIDAS).
Results: There were 1,697 eligible subjects for this study in the following categories: MM (5.5%), MAM (53.8%), or MUM (40.7%). Women with MM had an older age of migraine onset. Those with predominantly menstrually-related attacks (MM) had fewer headache-days but appeared to be more impaired by attacks. HIT-6 and MIDAS scores were significantly higher for both the MM and MAM groups compared with the MUM groups; however, effects were more robust for MM than MAM.
Conclusions: Nearly 60% of women with migraine reported an association between migraine and menses. These women reported greater headache impact and migraine-related burden on functioning than those in whom migraines were not related to menstruation. Women with MM were more impaired by attacks while women with MAM had overall highest burden, likely due to experiencing migraines on additional days.