The findings from 3 of the studies not yet discussed previously are briefly summarized.244 Using data from the Nurse s Health Study, Parker et al245 found that after multivariable adjustment, women with hysterectomy with bilateral oophorectomy had a slightly elevated risk of total stroke compared with women with hysterectomy with ovarian conservation (HR, 1.14; 95% CI, 0.98 1.33), and this associa- tion did not reach significance. In further analysis of these data limited to women with hysterectomy who had never used estro- gen therapy, the authors found a larger statistically significant association between oophorectomy and total stroke (HR, 1.85; 95% CI, 1.09 3.16) in all women and in women with hyster- ectomy before age 50 years (HR, 2.19; 95% CI, 1.16 4.14). A more recent analysis of a Swedish cohort found that women who underwent an oophorectomy before age 50 years had an increased risk of total stroke (HR, 1.47; 95% CI, 1.16 1.87) compared with women with no hysterectomy and no oopho- Finally, in a recent analysis of data from the WHI focused on women with a history of hysterectomy (without capture of age before natural menopause), no association was found for oophorectomy versus ovarian conservation and risk of total stroke in all women (HR, 1.04; 95% CI, 0.87 1.24) or those women without a history of hormone use (HR, 1.31; 95% CI, 0.92 1.87) after multivariable adjustment.247 Menopause Onset: Summary and Gaps Results of existing studies of the association between age at menopause or premature or early menopause, whether natural or surgical, and stroke risk appear to suggest increased risk of stroke with earlier onset of menopause, although the evi- dence is not entirely consistent. 