Information was obtained on: the timing and duration of non-contraceptive estrogen use, the names of the preparations and reasons for starting and stopping each episode of use; other drug use particularly oral contraceptives, aspirin, phenylpropanolamine; age at menopause; cigarette smoking; height and weight; histories of previous myocardial infarction, hypertension, pre-eclamptic toxemia, diabetes mellitus, angina pectoris and abnormal serum lipids; reproductive history; alcohol and coffee consumption; personality type based on the Framingham Type A Scale; family history of myocardial infarction; exercise; socioeconomic and life style factors; number of physician visits in last two years and total number of hospital admissions.