The relative impact of smoking and oral contraceptive use on women in the United States.

Women who smoke and use oral contraceptives (OCs) are at increased risk for cardiovascular and cerebrovascular disease. To study the prevalence of smoking and OC use and other behaviors affecting health, 28 states and the District of Columbia conducted telephone surveys during 1981 through 1983. More than 22,000 US adults were interviewed, of whom 5779 women aged 18 to 44 years were studied. Data were weighted to represent the US population. Overall, 7.4% of US women aged 18 to 44 years reported smoking and using OCs; 1.1% reported smoking 25 or more cigarettes per day while using OCs. Although women aged 18 to 24 years were most likely to smoke and use OCs, combined smoking and OC use contributed substantially to the number of excess cases of myocardial infarctions occurring among US women aged 35 to 44 years. However, regardless of OC use, smoking accounted for most of the excess cases. Therefore, health care providers need to intensify their efforts to reduce smoking among their patients.