Low-dose aspirin for migraine prophylaxis in women

Although migraine is more common among women than men, the only two large, randomized trials of low-dose aspirin for migraine prophylaxis have been conducted in men. As part of the Women's Health Study, an ongoing randomized trial of low-dose aspirin and vitamin E among 39 876 female health professionals aged 45 and older, 1001 women with frequent migraine attacks were assigned to 100 mg of aspirin every other day (n = 525) or aspirin placebo (n = 476). Migraine frequency, as well as severity, duration, and degree of incapacitation, were assessed by self-report on questionnaires 12 months and 36 months after randomization, and also by monthly diaries kept before and after randomization. Women assigned to aspirin reported small and consistent decreases in migraine frequency (59.6% vs. 56.4% assigned to placebo reporting improvement at 36 months; odds ratio 1.13, 95% confidence interval, 0.86--1.48), as well as decreases in severity, duration, and migraine-related incapacitation. These reductions were not, however, statistically significant. These data are compatible with a small treatment effect of low-dose aspirin in the prophylaxis of migraine among middle-aged women.