Oral contraceptives and nonfatal stroke in healthy young women. Ann Intern Med

obtained medical histories on 29 premenopausal women with a discharge diagnosis of stroke. Of these women, 14 were otherwise healthy with no known predisposing illnesses. Eleven of the 14 patients were taking oral contraceptives just before admission compared with seven of 56 otherwise healthy control women (13%). The relative risk estimate for stroke among oral contraceptive users compared with nonusers is 26 (lower 9 0 % one-sided confidence bound = 7.0). Cigarette smoking was only weakly associated with stroke in this group of women. PREVIOUS REPORTS suggest that women using oral con-traceptives have a greater risk of stroke than nonusers (1-4). To evaluate this association further, we have exam-ined data from the Boston Collaborative Drug Surveil-lance (BCDS) Program on oral contraceptive use and stroke. Our study was confined to potentially childbear-ing women who were otherwise healthy before their ad-mitting illnesses and had no contraindication to oral con-traceptive use. Subjects and Methods We obtained information for two groups of hospitalized pa-tients enrolled in the BCDS Program. The first group consisted of patients admitted since 1969 to selected general medical wards of 21 hospitals in the United States, Great Britain, Ne