All further analyses were restricted to current users of hormone therapy, with EE users as the reference group, and were conducted for MI and ischemic stroke cases and controls only. Because of the small number of hemorrhagic stroke cases, this group was not considered in CEE-EE comparisons. Compared with EE use, the use of CEE was not associated with an increased risk of MI (adjusted OR, 0.93; 95% confidence interval [CI], 0.65-1.31)or ischemic stroke (adjusted OR, 1.31; 95% CI, 0.88-1.97) (Table 4). The OR was little changed by additional adjustment for progestin use, heart failure, and number of physician visits in the year before the index date. Among users of estrogen alone (without progestin), there was no difference in MI risk between users of CEE and EE, but for ischemic stroke, there was a suggestion of higher risk associated with use of CEE alone compared with EE alone (OR, 1.57; 95% CI, 0.98-2.53; P = .06). Among women who used a high daily dose of estrogen (>0.625 mg), there was a suggestion of higher risk of MI (OR, 2.22; 95% CI, 0.82-5.97; P = .12) and ischemic stroke (OR, 2.59; 95% CI, 0.83-8.07; P = .10) associated with CEE use compared with EE use, but the number of subjects in these analyses was small and the CIs were wide. In addition, there was a suggestion of higher risk of MI associated with use of CEE initiated within 6 months of the index date compared with EE use initiated during the same period (OR, 2.33; 95% CI, 0.93-5.82; P = .07).