Estimates of the risk of cardiovascular death attributable to low-dose oral contraceptives in the United States

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.

O impacto do aborto ilegal na saúde reprodutiva: sugestões para melhorar a qualidade do dado básico e viabilizar essa análise

Estatísticas fidedignas sobre o aborto provocado, provenientes de países em que essa prática é legalizada, permitem uma adequada avaliação do impacto do aborto na Saúde Reprodutiva. Paradoxalmente, é justamente nesses países que observam-se os menores danos à Saúde da Mulher enquanto que, mesmo pautando-se em dados pouco ou nada confiáveis, o custo da prática clandestina é altíssimo: suas sequelas são bastante frequentes e, não raras vezes, levam ao óbito. Avaliar-se o quão alto é este custo, contudo, é uma tarefa bastante árdua e, infelizmente, dependendo do enfoque desejado pode até ser inexequível. A solução mais acertada para a resolução desse dilema seria, a julgar pela literatura especializada, legalizar-se o aborto. Nessa eventualidade, além de se reduzir, automaticamente, os custos da prática clandestina, a análise do dueto Aborto/ Saúde, por si, permitiria remover os custos remanecentes.Mas, enquanto se convive com uma legislação restritiva, a solução mais sensata, é buscar otimizar a qualidade de análise daquele dueto. Nesse sentido, pode-se recorrer à adoção de uma técnica estatística que remove o maior dos entraves na determinação da dinâmica do aborto ilegal - a saber, a sub-declaração e/ou sub-registro da frequência de recorrência ao aborto -, a TRA; bem como elaborar-se estudos populacionais, a partir de um plano de amostragem simplificado, sobretudo por serem raríssimos frente aos estudos baseados em dados hospitalares, apesar de fornecerem informações bem mais amplas sobre a dinâmica do aborto.

Long-term benefits and risks of alternative methods of fertility control in the United States

A risk-benefit analysis of five alternative approaches to fertility control among US women over the age of 30 was performed: tubal ligation, vasectomy, intrauterine device, barrier method (condom), and combined oral contraceptives. Taken into account were age-specific probabilities of contraceptive failure, fecundability, spontaneous abortion, reproductive mortality (ectopic pregnancy, delivery, or induced abortion), life table mortality, and mortality from specific cancer sites (ovarian, endometrial, breast, and prostate) and cardiovascular disease. Relative to women using no contraceptive precautions, the use of any method of contraception between the ages of 30 and 50 was associated with net benefit in terms of averted deaths. However, when duration of observation was extended up to age 80, we predicted an excess of about 880 deaths from prostate cancer per 100,000 users of vasectomy. Other methods continued to be associated with net benefit, ranging from 130 to 360 deaths averted per 100,000 users. It was concluded that the non-reproductive risks and benefits of contraceptive methods continue to be relevant long after the reproductive years. The balance of risks and benefits may differ in other countries with different cause-specific and life table mortality rates.

Reproductive mortality and its relation to different methods of birth control

This report evaluates the decrease in maternal mortality and its relation to family planning methods in Sweden during the years 1911-80. In the 1930s fertility was low but illegal abortions were at a high level and the associated maternal death rate was 18.5 per 1000 women. With the legalization of abortion and the introduction of modern contraceptive methods, the crude reproductive mortality rate in 1965-70 was 1.7 per 100,000 women and this was reduced still further, especially for younger women, by the late 1970s. Standardized reproductive mortality was then 80% higher than the crude rate, indicating the importance of modern family planning methods. Mortality associated with oral contraceptive or IUD use in Sweden during the 1960s and 1970s was lower than in England and the US. Mortality associated with sterilization was 6.2 per 100,000 procedures.

Reproductive mortality in the United States: recent trends and methodologic considerations

Between 1975 and 1982, the annual number of deaths attributable to pregnancy and childbirth, induced abortion, and contraception in the United States declined from 1,083 to 751. The mortality rates for each of these components decreased by 35,89, and 35 per cent, respectively, and the overall reproductive mortality rate dropped by 35 per cent. The death rate due to pregnancy and childbirth is 25 times greater than that due to induced abortion and eight times more than that to contraceptive-associated mortality. In 1982 nearly 30 million women used contraceptives, while slightly fewer than four million women were pregnant to term. The decrease in contraceptive-associated mortality between 1975 and 1982 probably reflects a combination of safer contraceptives, fewer women using contraceptive methods that may not be safest for them, and an increasing number of sterilizations, which remove women from the group at highest risk of contraceptive-related mortality. Maternal mortality appears to be slowing its rate of decline, while induced abortion mortality has been very low since the legalization of abortion.

Smoking cessation with young women in public family planning clinics: the impact of physician messages and waiting room media

This study evaluated the impact of a media program and a physician-delivered message in encouraging smoking cessation among young black women in public family planning clinics. Incorporated into the clinic visit, the 3- to 5-min physician message was intended to elicit a commitment from participants to take steps toward quitting, namely, to think about quitting, set a target date, enlist the help of family and friends, throw away matches and cigarettes, and to then quit "cold turkey." The media program consisted of specially designed posters in waiting rooms showing models of people in the process of quitting and a continuously run movie dealing with women and smoking. A total of 1,179 female smokers were recruited into the study when they came to three separate clinics in Baltimore, Maryland, to receive gynecological examinations and/or contraceptive services. Four separate interventions were tested: (I) a baseline questionnaire about smoking habits and related information; (II) baseline questionnaire plus media program; (III) baseline questionnaire plus physician message; and (IV) baseline questionnaire plus media program plus physician message. Conditions I and II were administered in Clinic A on alternating weeks, Condition III was administered in Clinic B, and Condition IV was administered in Clinic C. Follow-up was conducted at 3 and 12 months. Follow-up rates were 88.1% at 3 months, 79.9% at 12 months, and 84.1% for both 3 and 12 months. Among women receiving the physician message (Conditions III and IV), 9.9% reported not smoking at 12 months; the lowest selfreported cessation rate was 3.1% in Condition I. When verified through analyzing cotinine in saliva, quit rates were 0.09% in Condition I, 2.4% in Condition II, 3.7% in Condition III, and 2.1% in Condition IV. The fact that participants receiving the physician message quit smoking at a significantly greater rate than those who did not indicates the need for further study of the impact of physician-delivered smoking cessation messages and ways to increase their effectiveness.

Perceptions of contraceptive methods: a multidimensional scaling analysis

This study employed similarity judgments to determine the dimensions used in distinguishing between methods of contraception, and to investigate individual differences in the use of these dimensions. Three groups of subjects rated the similarity of seventeen methods of contraception, and also rated each method on a number of adjective scales. Multidimensional scaling of the similarity judgments revealed two dimensions: one related to effectiveness, expense, and safety, and the other differentiating between standard and non-standard methods of contraception (or natural and non-natural ones). In addition, methods of contraception were arrayed in the space mainly on the basis of physical similarity. Analyses of the rating scales indicated that subjects perceived methods accurately in terms of effectiveness, but were inaccurate in their ratings of safety to the user. Finally, analysis of individual differences indicated that the second dimension was more salient to younger than to older subjects, but did not reveal differences related to religion or contraceptive use.

Depo-Provera--ethical issues in its testing and distribution

Ethical issues relating to the use of the injectable contraceptive in developed and developing countries alike involve public policy decisions concerning both criteria for testing a new drug and individual choices about using a specific form of contraception approved for national distribution. Drug testing consists of an important but still evolving set of procedures. Depo-Provera is not qualitatively different from any other drug and some unpredictable risks are inevitable, even after extensive animal experiments and clinical trials. In assessing the risks and benefits of Depo-Provera use, epidemiological data from large-scale human use is now beginning to become more important than data from animal experiments and clinical trials. The consumer's best interest is central to any ethically responsible system of drug distribution. Systems of informed choice are needed, even in societies where illiteracy remains common and medical services are weak. In the case of a contraceptive, the risks of non-use leading to unintended pregnancy, which can result in high mortality, are relevant as well as the side-effects of the method. An attempt, therefore, is made here to categorise those issues which are universal and those which are country-specific.

Mortality risk associated with tubal sterilization in United States hospitals

Despite the millions of women who have undergone tubal sterilization in United States hospitals, little has been published about the risk of death from these procedures. To estimate a case-fatality rate of tubal sterilization, we combined data from the Commission on Professional and Hospital Activities and the National Center for Health Statistics with a review of the clinical circumstances for each woman whose death was identified as being potentially sterilization attributable. Considering all deaths temporally associated with tubal sterilization, we estimate that the case-fatality rate is nearly 8/100,000 procedures. When only deaths determined to be attributable to the sterilization operation per se are considered, the case-fatality rate is approximately 4/100,000 procedures, making death attributable to tubal sterilization a rear event.

Mortality risk associated with female sterilization

The mortality risk associated with female sterilization in an analysis of 255 812 procedures performed in developing countries from 1973 to 1979 is reviewed. Fifteen sterilization-related deaths were reported during this period. The overall mortality was 5.86/100 000 procedures. The most common cause of death was the result of anesthetic complications, with infection in second place. The risk of death by procedure was higher with culdoscopy than with minilaparotomy or laparoscopy. The authors believe that low mortality figures are realistic and can be achieved in developing countries when experienced surgical teams are provided with adequate facilities, observe strict medical standards, utilize minilaparotomy and laparoscopy and avoid general and spinal anesthesia.

Risk of exogenous estrogen therapy and endometrial cancer

A retrospective study was carried out on 431 patients with endometrial cancer and 431 control subjects matched as to age, race, and parity. They were seen at Duke University Medical Center from 1940 to 1975. The study was performed in order to evaluate the risk of exogenous estrogen therapy and the development of adenocarcinoma of the endometrium. The overall risk was 2.38, with certain subgroups demonstrating different degrees of risk. Increased risk was associated with estrogen therapy of longer than 5 years' duration in white patients. The risk also was confined to Stage I, grade 1 lesions and more superficial myometrial invasion. Five-year survival for patients who used estrogen replacement and had Stage I, grade 1 lesions was 94.7%. The risks associated with exogenous estrogens are real but should be considered in a risk/benefit context when prescribing for the needs of an individual patient.

Oral contraceptive hypertension and thromboembolism

Oral contraceptives (OCs) are a highly effective and widely accepted means of avoiding pregnancy, but they also worsen the major atherogenic cardiovascular risk factors to some degree in all women. Some OC users may suffer severe hypertensive episodes or massive hypertriglyceridemia with pancreatitis. Mild or severe adverse effects could eventually have serious consequences beyond the childbearing years. OC use would appear imprudent for women with a history of hypertension, gestational hypertension and a family history of hypertension. Special care is needed with blacks, diabetics and women with renal disease. OCs may also affect blood clotting, fibrinolysis and platelet adhesiveness. Also, histochemical and anatomical changes in blood vessels have been noted. Both may precipitate thromboembolic events while the OC user is still at the childbearing age and may also contribute to accelerated atherogenesis in subsequent years. There is a need for more specific guidelines for monitoring women on OCs for a worsening of their cardiovascular risk profile and changes in blood coagulation. Indications and contraindications for OC use in relation to the hazard of thromboembolic sequelae need to be more explicitly defined.

Barrier methods of contraception: a reappraisal

In the last two years, there has been a gradual reawakening of interest in barrier methods and an increase in their usage by both men and women. This is in large part due to concern about the sometimes serious side effects reported for other contraceptive methods. The return to these techniques is particularly important, given the current epidemics of teenage pregnancy and veneral disease. One of the major problems in relation to barrier methods today is the accurate determination of their efficacy. There are very limited data with statistical validity available to judge the exact rate of effectiveness one might obtain using one of these techniques. The National Survey of Family Growth, conducted by the National Center for Health Statistics, showed a failure rate per 100 women of 16.7 for foam, cream or jelly and 15.9 for diaphragms (22). There is a great need for new and improved barrier methods of contraception. Numerous clinical studies are being set up to test spermicidal agents and vaginal sponges for the female, as well as such things as disposable condoms for males.

Contraceptive practice and repeat induced abortion: an epidemiological investigation

The relationship between abortion experience and contraceptive practice is examined among women having a first or repeat induced abortion at the same clinic(n=443 in each group). A previous abortion was the single most important predictor of past contraceptive practices and of contraception at the conception of the pregnancy being terminated. A previous abortion was associated with greater use of all methods of contraception among women not on welfare (P < 0·001). During the 18–month study the proportion of patients who had had previous abortions rose from 13·3% to 21·1%, and those undergoing repeat abortions appeared increasingly likely to be on welfare. Contraceptive practies did not change over time except for women on welfare having repeat abortions who became less likely to have used contraception at the time of conception (p < 0·05). While the experience of abortion is generally associated with improved contraceptive practice, many women in this population, particularly those on welfare, appear to remain exposed to unprotected coitus and subsequent repeat abortion.

Oral and intrauterine contraception: a 1978 risk assessment

This report reviews the current literature on the various risks associated with the use of oral contraceptives and intrauterine contraceptive devices. Reports on oral contraceptives from large prospective studies are not beginning to supplement the detailed reports resulting from earlier case-control studies. These studies suggest that in Western societies there is an increase in the incidence of a variety of circulatory diseases, with an increased risk of death. With intrauterine contraceptive devices it now has been fairly well documented that there is an increased risk of pelvic inflammatory disease. After reviewing and assessing the risks of both methods in some detail and comparing these risks to the benefits, the resultant conclusion is that the benefits continue to outweigh the risks for both methods, except for older women who choose oral contraceptives and also are heavy smokers.

Pathogenesis of acute pelvic inflammatory disease: role of contraception and other risk factors

In a case-control study of matched pairs, the risk of acute pelvic inflammatory disease (PID) was 4.4 times higher in intrauterine contraceptive device (IUD) users than in nonusers (p less than 0.001). Of approximately 500,000 cases of acute PID occurring annually in the United States, an estimated 110,000 are attributable to IUD's, costing over forty-four million dollars per year. PID was attributable to the IUD in 77 per cent of IUD users. No particular type of IUD was implicated. The relative risk of acute PID in IUD users over nonusers was higher in nulligravid women than in previously pregnant women and was directly related to socioeconomic status (SES), but the total annual risk of PID in IUD users appear inversely related to SES. IUD use significantly increased the risk of nongonococcal PID. Fever occurred in 13 (21 per cent) of 61 IUD users and 59 (41 per cent) of 143 nonusers (p less than 0.025). Among women with nongonococcal PID, and adnexal mass greater than or equal to 6 cm. was noted in 14 (40 per cent) of 35 IUD users and in only 12 (15 per cent) of 78 nonusers (p less than 0.01). An increased risk of gonococcal PID was found among non-Caucasians and women not using contraception, while the risk of nongonococcal PID was increased among women with a past history of gonorrhea. Oral contraceptive use may protect women with gonorrhea from developing PID. Menstruation precipitates the onset of symptoms of gonococcal PID.

Medical supervision for contraception: too little or too much?

The need to provide medical supervision in contraceptive services is reviewed in the context of the situation existing in developing nations. The author contends that less rather than more medical supervision can be justified if one compares the relatively low incidence of complications from modern contraception with the inordinately high maternal death rates from pregnancy and its complications in these same countries.

The benefits and risks of IUD use

Next to combination oral contraceptives (OCs), intrauterine contraceptive devices (IUDs) are the most effect form of contraception available. IUDs require only one-time motivation, cause no systemic metabolic effects, and do not depend on continued action of the user for effectiveness. Risks, side effects and complications of this method, including expulsion, perforation pain, bleeding and infection, are reviewed.

Mortality and fertility control

The authors present a continuation of the thesis suggesting that the most rational procedure for regulating fertility is a perfectly safe, even though not completely effective, contraceptive method combined with safe methods for terminating pregnancy when the contraceptive fails. This analysis demonstrates that, compared with the risk of death from pregnancy and childbirth, major reversible methods of fertility control--the pill, IUDs, condoms, and diaphragms--and abortion are associated with very low levels of mortality. The exception to this statement is pill use after age 40 by women who smoke. This analysis also confirms the very low mortality associated with using the condom and diaphragm with early induced abortion as a backup to terminate pregnancies resulting from contraceptive failures.

Cardiovascular-disease mortality trends and oral-contraceptive use in young women

Analysis of mortality trends in 21 countries indicates that, since oral contraceptives first became available, changes in mortality from non-rheumatic heart-disease and hypertension (I.C.D. 400-429), cerebrovascular disease (I.C.D. 430-439), and all non-rheumatic cardiovascular diseases (I.C.D. 400-469) among women aged 15-44 years have been strongly associated with changes in the prevalence of oral-contraceptive use in each country. This relationship is highly specific for women of reproductive age. The relative risks of death from heart-disease and hypertension, cerebrovascular disease, and all cardiovascular diseases for women using oral contraceptives compared with non-users were estimated to be 5 to 1,2 to 1, and 3 to 1 respectively. These findings suggest that the range of vascular diseases affected by oral-contraceptive use and the size of the associated risks may be greater than previously recognised. Furthermore, the increased risks of cardiovascular disease might exist not only with the pills containing high oestrogen doses, but also with the new "lower dose" pills.