Objective: Our purpose was to estimate the annual risk of death in the United States from cardiovascular disease attributable to low-dose combination oral contraceptives.
Study design: Estimates of the risk of death from cardiovascular disease attributable to low-dose oral contraceptives were modeled on data from studies published through 1997 and from age-specific mortality rates in the United States for 1993 and 1994.
Results: Attributable risk of death from cardiovascular disease resulting from oral contraceptive use is 0.06 and 3.0 per 100,000 nonsmokers 15 to 34 years of age and 35 to 44 years of age, respectively. In smokers this risk increases, respectively, to 1.73 and 19.4 per 100,000 users in these 2 age groups; however, 97% and 85% of this risk is due to the combined effects of smoking and using oral contraceptives. The attributable risk of death from cardiovascular disease in nonsmoking oral contraceptive users is lower than the risk of death from pregnancy in nonusers of oral contraceptives at all ages; however, among smoking oral contraceptive users more than 35 years of age, the excess risk of death from oral contraceptives is higher than the risk of death from pregnancy.
Conclusion: There is virtually no excess attributable risk of death from cardiovascular disease related to oral contraceptive use in young women. However, smokers more than 35 years of age should use a nonestrogen contraceptive.
PIP: The annual risk of death in the US from cardiovascular disease attributable to low-dose combination oral contraceptives (OCs) was estimated through use of data from studies published in 1980-1997 and from age-specific mortality rates for 1993 and 1994. Four cardiovascular disease categories were included: myocardial infarction, venous thromboembolism and pulmonary embolism, ischemic stroke, and hemorrhagic stroke. The overall risk of death from cardiovascular disease among nonsmoking users of low-dose OCs is 0.06/100,000 women in the 15-34 year age group and 3.03/100,000 women in the 35-44 year age group. For young nonsmokers, the excess mortality risk associated with OC use is smaller than the risk of death from pregnancy, whether terminated by abortion or carried to term. Among OC users who smoke, the risk of cardiovascular mortality is 1.73/100,000 in 15-34 year olds and 19.4/100,000 in women 35-44 years old; however, 97% and 85% of this risk, respectively, is composed of the combined OC-smoking risk. Among smoking OC users over 35 years of age, the excess risk of death from OCs exceeds the risk of death from pregnancy. Young nonsmokers raise their risk of death from cardiovascular disease by less than 10% (0.60-0.65/100,000) by using OCs, while young women who do not use OCs increase their risk of death by 260% (0.60-1.57/100,000) by smoking cigarettes. For older women, the corresponding increases are 95% among nonsmoking OC users and 315% among smoking nonusers. These estimates indicate that women over 35 years of age who smoke should not be permitted to use either low- or high-dose OCs because of the excess attributable risk of death from cardiovascular disease.