Tibolone is also associated with an increased risk of stroke. Prospective randomized trials of alternative forms of HT are ongoing, although the primary outcomes are an intermediate measurement of subclinical atherosclerosis and not stroke. The use of HT for other indications needs to be informed by the risk estimate for vascular outcomes provided by the clinical trials that have been reviewed. HT is associated with a small to moderate improvement in sex- ual function, particularly in pain, when used in women with menopausal symptoms or in early postmenopause (within 5 years of amenorrhea), but this treatment cannot be recom- mended currently for stroke prevention in unselected post- Limitations of prior trials included low adherence, high attrition, inadequate power to detect risks for low-incidence outcomes such as stroke, and evalu- ation of few regimens. Further research is needed to better understand the subgroups of women who may be at risk for stroke associated with HT and to optimize the timing and route of administration, as well as the dose and type of hor- mone used. Much less is known about the use of HT and the risk of either ICH or SAH. Postmenopausal HT: Recommendations 1. HT (CEE with or without medroxyprogesterone) should not be used for primary or secondary preven- tion of stroke in postmenopausal women (Class III; Level of Evidence A). 2. Selective estrogen receptor modulators, such as ral- oxifene, tamoxifen, or tibolone, should not be used for primary prevention of stroke (Class III; Level of Evidence A). Risk Factors More Common in Women Than Men Migraine With Aura The prevalence of migraine in the population is 18.5%, and for migraine with aura, it is 4.4%.277 Women are 4 times more likely to have migraines than men.277 Very rarely are migraines associated with stroke, however. 