Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

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.

Breast cancer and hormonal contraceptives: further results. Collaborative Group on Hormonal Factors in Breast Cancer

The Collaborative Group on Hormonal Factors in Breast Cancer has brought together and reanalysed the worldwide epidemiological evidence on breast cancer risk and use of hormonal contraceptives. Original data from 54 studies, representing about 90% of the information available on the topic, were collected, checked and analysed centrally. The 54 studies were performed in 26 countries and include a total of 53,297 women with breast cancer and 100,239 women without breast cancer. The studies were varied in their design, setting and timing. Most information came from case-control studies with controls chosen from the general population; most women resided in Europe or North America and most cancers were diagnosed during the 1980s. Overall 41% of the women with breast cancer and 40% of the women without breast cancer had used oral contraceptives at some time; the median age at first use was 26 years, the median duration of use was 3 years, the median year of first use was 1968, the median time since first use was 16 years, and the median time since last use was 9 years. The main findings, summarised elsewhere, are that there is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in the past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. In addition, the cancers diagnosed in women who had used oral contraceptives tended to be less advanced clinically than the cancers diagnosed in women who had not used them. Despite the large number of possibilities investigated, few factors appeared to modify the main findings either in recent or in past users. For recent users who began use before age 20 the relative risks are higher than for recent users who began at older ages. For women whose use of oral contraceptives ceased more than 10 years before there was some suggestion of a reduction in breast cancer risk in certain subgroups, with a deficit of tumors that had spread beyond the breast, especially among women who had used preparations containing the highest doses of oestrogen and progestogen. These findings are unexpected and need to be confirmed. Although these data represent most of the epidemiological evidence on the topic to date, there is still insufficient information to comment reliably about the effects of specific types of oestrogen or of progestogen. What evidence there is suggests, however, no major differences in the effects for specific types of oestrogen or of progestogen and that the pattern of risk associated with use of hormonal contraceptives containing progestogens alone may be similar to that observed for preparations containing both oestrogens and progestogens. On the basis of these results, there is little difference between women who have and have not used combined oral contraceptives in terms of the estimated cumulative number of breast cancers diagnosed during the period from starting use up to 20 years after stopping. The cancers diagnosed in women who have used oral contraceptives are, however, less advanced clinically than the cancers diagnosed in never users. Further research is needed to establish whether the associations described here are due to earlier diagnosis of breast cancer in women who have used oral contraceptives, to the biological effects of the hormonal contraceptives or to a combination of both. Little information is as yet available about the effects on breast cancer risk of oral contraceptive use that ceased more than 20 years before and as such data accumulate it will be necessary to re-examine the worldwide evidence.

CDC WONDER: a comprehensive on-line public health information system of the Centers for Disease Control and Prevention

OBJECTIVES

CDC WONDER, a comprehensive on-line public health information system of the Centers for Disease Control and Prevention (CDC), was developed to place timely, action-oriented information in the hands of public health professionals.

METHODS

A unified system was developed de novo to be used for and to evolve along with public health. All data are stored and updated on the CDC mainframe.

RESULTS

CDC WONDER provides menu-driven access to 24 databases with information on mortality, hospital discharges, cancer incidence, notifiable diseases, acquired immunodeficiency syndrome, the Morbidity and Mortality Weekly Report, etc.; each database has on-line documentation. Results can be tabulated and graphed, and there is full-text searching of textual databases. Non-CDC staff have access via telephone connection. From August 1991 through June 1992, system databases were accessed 10,698 times, and there were 842 users (mean of 97 new users per month).

CONCLUSIONS

CDC WONDER has shown that it is possible to build a large, on-line database of scientific data for public health professionals. CDC WONDER provides a common foundation from which to build information-based public health plans and policy and could help strengthen the public health system.

Age-specific differences in the relationship between oral contraceptive use and breast cancer

BACKGROUND

Nearly all studies have suggested that the use of oral contraceptives (OC) is not associated with the aggregate risk of breast cancer diagnosed in women aged 20-54 years. Because of age-specific differences in the breast cancer-parity relationship and because of age-specific differences in other breast cancer risk factors, the Centers for Disease Control reexamined data from the Cancer and Steroid Hormone Study (CASH) to assess whether OC use has different effects on the risk of breast cancer at different ages of diagnosis.

METHODS

This population-based case-control study was designed to examine the relationship between the use of OC and the risk of breast, ovarian, and endometrial cancer. CASH was conducted in eight geographic areas in the United States during 1980-1982. All participants were interviewed at home with a pretested standardized questionnaire including a calendar of life events and a photograph book of all pills marketed in the United States.

RESULTS

We found that the relationship between the risk of breast cancer and OC use appeared to vary by the age at diagnosis. Among women aged 20-34 years at diagnosis or interview, those who had ever used OC had a slightly increased risk of breast cancer (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.0-2.1) compared with women of the same ages who had never used OC. Among these women, there were no trends of increasing or decreasing risk with any measure of OC use. Among women aged 35-44 years, there was no association between OC use and breast cancer. Among women aged 45-54 years, those who used OC had a slightly decreased risk of breast cancer (OR, 0.9; 95% CI, 0.8-1.0). Among these women, risk estimates decreased significantly with increasing time since first and last use.

CONCLUSIONS

Although the slightly increased risk estimates for the youngest women were compatible with findings by other investigators, the decreased risk estimates for the oldest women have not been described in as many studies. Available data provide no reasons to change prescribing practices or the use of OC that are related to the breast cancer risk.

Age-specific differences in the relationship between oral contraceptive use and breast cancer

Nearly all studies have suggested that the use of oral contraceptives (OC) is not associated with the aggregate risk of breast cancer diagnosed in women aged 20-54. Because of age-specific differences in the breast cancer-parity relationship and because of age-specific differences in other breast cancer risk factors, the Centers for Disease Control reexamined data from the Cancer and Steroid Hormone Study to assess whether OC use has different effects on the risk of breast cancer at different ages of diagnosis. This was a population-based case-control study conducted in eight geographic areas in the United States during 1980-1982. In these data, the relationship between the risk of breast cancer and OC use appeared to vary by age at diagnosis. Among women aged 20-34 years at diagnosis or interview, those who had ever used OC had a slightly increased risk of breast cancer (odds ratio 1.4, 95% confidence interval 1.0-2.1) when compared with women of the same ages who had never used OC. Among these women, there were no trends of increasing or decreasing risk with any measure of OC use. Among women aged 35-44 years, there was no association between OC use and breast cancer. Among women aged 45-54 years, those who used OC had a slightly decreased risk of breast cancer (odds ratio 0.9, 95% confidence interval 0.8-1.0). Among these women, the risk estimates decreased significantly with increasing time since first and last use. Although the slightly increased risk estimates for the youngest women are compatible with findings by other investigators, the decreased risk estimates for the oldest women have not been described in as many studies. Available data provide no reasons for changes in prescribing practices or in the use of OC as related to breast cancer risk.

The independent associations of parity, age at first full term pregnancy, and duration of breastfeeding with the risk of breast cancer. Cancer and Steroid Hormone Study Group

Although the important influence of a woman's reproductive history on her risk of breast cancer is widely recognized, it is not clear whether this is wholly accounted for by the age at her first full-term pregnancy, or whether there are additional, independent influences of breastfeeding or number of children. To examine the respective contributions to the risk of breast cancer of these reproductive factors, we used logistic regression methods to analyze data from a multicenter case-control study, the Cancer and Steroid Hormone Study. Included in the analysis were 4599 women, 20-55 years of age, identified as having an initial diagnosis of breast cancer by one of eight collaborating population-based cancer registries. The 4536 controls were women of similar ages selected by random dialing of households with telephones in the same eight areas. As expected, age at first full-term pregnancy exerted a strong influence on the risk of breast cancer. However, after it and other potentially confounding factors had been controlled for, parity and duration of breastfeeding also had a strong influence on the risk of breast cancer. Compared with women of parity one, women of parity seven or greater had an adjusted relative risk of breast cancer of 0.59 (95% CL, 0.44-0.79). Compared with parous women who never breastfed, women who had breastfed for 25 months or more had an adjusted relative risk of 0.67 (0.52-0.85). These results do not support the supposed preeminent importance of age at first full-term pregnancy among the reproductive determinants of breast carcinogenesis. Resolution of this issue may have important implications for elucidating hormonal influences on breast cancer and for projecting future trends in the disease.

The evaluation of the data collection process for a multicenter, population-based, case-control design

This report details the methods the authors used to conduct the Cancer and Steroid Hormone Study, a multicenter, population-based, case-control study of oral contraceptive use in relation to breast, endometrial, and ovarian cancer diagnosed during 1980-1982. The authors have documented their methods and rationale, and the results of their data collection efforts as a practical guide for the planning and conduct of large case-control studies. They observed the following: 1) the Surveillance, Epidemiology, and End Results program is a useful epidemiologic resource for identifying cases from which to evaluate risk factors for cancer in the United States; 2) random digit dialing is an effective and efficient method for screening for eligible controls for a population-based study; 3) with the cooperation of community pathologists, histologic specimen slides can be retrieved and reviewed for diagnostic confirmation and histologic subclassification of cancer for greater than 95% of the cases interviewed; and 4) data reported during personal interviews of study participants can be validated by reviewing medical records for more than 75% of study participants who reported medical events that occurred during the 10 years before the beginning of the study.

The risk of breast cancer in postmenopausal women who have used estrogen replacement therapy

We studied the association between estrogen replacement therapy (ERT) and the risk of breast cancer as part of the Cancer and Steroid Hormone Study. All subjects in the analysis were postmenopausal women enrolled from eight geographic areas. Women 25 to 54 years old with newly diagnosed breast cancer were identified through population-based tumor registries and diagnosed between Dec 1, 1980, and Dec 31, 1982. Controls were selected from the same eight geographic areas by the random digit dialing of residential telephone numbers. Analyses included 1369 cases and 1645 controls. Among women with bilateral oophorectomy, the relative risk of breast cancer for women who had ever used ERT was 1.3, compared with women who had never used ERT. Among women who had undergone hysterectomy but who still had at least one ovary, the relative risk was 1.1; among women who reported a natural menopause, the relative risk was 0.8. Overall, the risk of breast cancer did not appear to increase appreciably with increasing ERT duration or latency, even for durations and latencies of 20 years or longer.

Assessment of screening as a preventive technology: the example of HTLV-III/LAV antibody testing

Screening for disease control can be defined as a preventive technology that is used to examine asymptomatic people in order to classify them as likely or unlikely to have the disease that is the object of screening. Screening may consist of routine physical examinations, radiologic procedures, semi-invasive procedures such as endoscopy, or serologic tests. In this paper, a new serologic test is considered. Acquired immunodeficiency syndrome (AIDS) is a devastating disease with high mortality, recently shown to be caused by a retrovirus named human T-lymphotropic virus Type III (HTLV-III) or lymphadenopathy-associated virus HTLV-III antibody in serum specimens. Performance characteristics are excellent with high sensitivity and specificity when reactive serum specimens are checked for consistency of response by enzyme immunoassay (EIA). This test is now part of the screening protocol for all blood donation centers to decrease the risk of HTLV-III transmission via blood or blood products. About 0.2% (1 in 400) of blood donors have repeatedly reactive EIA tests to HTLV-III antibody. Approximately one-third of these donors have other laboratory evidence of infection. Screening for HTLV-III is a new technology that illustrates virtually all of the factors that need consideration in an assessment of disease screening. This paper explores these technical, epidemiologic, economic, legal, social, and ethical factors.

The mortality risk associated with hysterectomy

To study the risks of mortality associated with hysterectomy that are specific to age, race, surgical approach, and associated conditions, we used data collected by the Commission on Professional and Hospital Activities during 1979 and 1980. Four hundred seventy-seven deaths were recorded among 317,389 women having abdominal hysterectomies and 46 deaths among 119,972 women having vaginal hysterectomies. The mortality rates for hysterectomy, standardized for age and race, were higher for procedures associated with pregnancy or cancer than for procedures not associated with these conditions (29.2, 37.8, and 6.0 per 10,000 procedures, respectively). Hysterectomies associated with pregnancy or cancer constituted 8% of all hysterectomies performed. However, 61% of all deaths occurred in women with pregnancy- or cancer-related conditions. The mortality rate associated with hysterectomy increased with age and was twice as high among black women.

Family history and the risk of breast cancer

To investigate whether a family history of breast cancer increases a woman's risk of developing breast cancer, we analyzed data from the Centers for Disease Control's Cancer and Steroid Hormone Study. The 4,735 cases were women 20 to 54 years old with a first diagnosis of breast cancer ascertained from eight population-based cancer registries; the 4,688 controls were women selected at random from the general population of these eight areas. Compared with women without a family history of breast cancer, women who had an affected first-degree relative had a relative risk of 2.3; women with an affected second-degree relative had a relative risk of 1.5; and women with both an affected mother and sister had a relative risk of 14. The risk of breast cancer for a woman was higher if her first-degree relative had unilateral rather than bilateral breast cancer or had breast cancer detected at a younger rather than older age. For women aged 20 to 39, 40 to 44, and 45 to 54 years, the estimated annual incidence of breast cancer per 100,000 women attributable to a first-degree family history of breast cancer was 51.9, 115.1, and 138.6, respectively, and that attributable to a second-degree family history of breast cancer was 12.1, 19.2, and 92.4, respectively.

Endometrial cancer: how does cigarette smoking influence the risk of women under age 55 years having this tumor?

This analysis of the Cancer and Steroid Hormone Study, a multicenter, population-based case control investigation of hormone use by women of reproductive age and endometrial, breast, and ovarian cancer shows that cigarette smoking is not associated with either an increased or a decreased risk of endometrial cancer. This study included 437 women with endometrial cancer and 3200 control subjects, all of whom were between the ages of 20 and 54 years at the time of interview. The absence of any alteration of the risk of endometrial cancer and smoking was found consistently no matter which variable was used as a measure of smoking--ever or never smoked cigarettes, former or current smoking, light or heavy smoking, or age smoking began.

Confirmation of the preoperative diagnoses for hysterectomy

Few previous studies have examined the relationship between the preoperative and pathologic diagnoses for hysterectomy. To determine the percentage of preoperative diagnoses that were confirmed by pathologic examination, we analyzed data from the Collaborative Review of Sterilization, a multicenter study of hysterectomies and tubal sterilizations in women aged 15 to 44 years. Data were collected from patient interviews and chart reviews. Of the 1851 women included in this study, 1283 (69%) had abdominal hysterectomies and 568 (31%) had vaginal hysterectomies. Overall, 52% of the hysterectomies were performed for a preoperative diagnosis that could potentially be confirmed by pathologic examination. Pathologic examination actually confirmed the preoperative diagnosis of endometrial hyperplasia in 95% of the cases, cervical intraepithelial neoplasia in 89%, leiomyomas in 84%, pelvic inflammatory disease in 75%, adenomyosis in 48%, and endometriosis in 47%. Among all of the potentially confirmable diagnoses, 80% were confirmed. The remaining 48% of the women who had hysterectomies had preoperative diagnoses that were not amenable to confirmation by pathology. Most of these were for one of three diagnoses: menstrual bleeding disorders, pelvic pain, or pelvic relaxation. In 47% of these cases, pathologic examination showed leiomyoma or adenomyosis; no abnormalities were found in 38% of these cases.

Tubal sterilizations performed in freestanding, ambulatory-care surgical facilities in the United States in 1980

In 1981 the American Association of Gynecologic Laparoscopists and the Division of Reproductive Health, Centers for Disease Control, jointly conducted a study of tubal sterilizations performed in 141 freestanding, ambulatory-care surgical facilities in 1980 in the United States. Information was collected through mailed questionnaires and telephone interviews. Of 330 potential responding facilities, 141 we identified as freestanding, ambulatory-care surgical facilities. About 16,500 tubal sterilizations were performed in these facilities in 1980. The mean number of tubal sterilizations per freestanding, ambulatory-care surgical facility was 212. Sixty-seven percent of tubal sterilizations were performed in the south and west. General anesthesia was the anesthetic method used in 97% of the procedures. Nearly 91% of tubal sterilizations were done via laparoscopy, with bipolar electrocoagulation the tubal-occlusion method used most frequently. After tubal sterilization the patients were observed for an average of 2.4 hours before discharge. The average cost of laparoscopic tubal sterilization was $801; for nonlaparoscopic tubal sterilization it was $850.

Mortality among young black women using contraceptives

Data on the risk of death associated with various contraceptive methods are incomplete. Therefore, we analyzed the mortality rates for young, black inner-city women who used one of four methods of contraception--oral contraceptives, depomedroxyprogesterone acetate, intrauterine (contraceptive) devices, and barrier methods. The subjects were 30,580 15- to 44-year-old women who enrolled at a family planning clinic between 1967 and 1972 and who were observed by monitoring death certificates through the end of 1977. Forty percent of the 218 deaths observed were from accidents and violence. Use of this family planning clinic greatly reduced the risk of death from childbearing; only two deaths were associated with pregnancy and childbirth, compared with the 24 deaths expected. Overall, users of the four methods died at similar, low rates. Given that this study involves considerable loss to follow-up, possible acute effects of contraceptives (eg, infections or thrombosis) are more accurately estimated than possible long-term effects (eg, cancer).

Menstrual changes after tubal sterilization

The authors used data from a multicenter prospective study of female sterilization surgery to study changes in menstrual function following tubal sterilization. Duration of menstrual bleeding, menstrual cycle length, cycle regularity, amount of menstrual bleeding, menstrual pain, and intermenstrual bleeding were examined. The authors followed 2456 women for two years after tubal sterilization surgery. Each woman served as her own control; her menstrual function at the two-year follow-up interview was compared with her menstrual function at the preoperative interview. Except for menstrual pain among women who underwent unipolar electrocoagulation procedures, there was no increase in the prevalence of adverse menstrual function after tubal sterilization. For all menstrual variables, 50% or more of women with adverse function preoperatively had an improvement by two years after tubal sterilization.

Alcohol consumption and risk of breast cancer

To investigate whether women who consume alcoholic beverages have a greater risk of breast cancer than women who never drink data from a population-based, case-control study, the Centers for Disease Control's Cancer and Steroid Hormone Study, were examined. During the first 15 months of data collection, 1226 women aged 20--54 with newly diagnosed breast cancer and 1279 women of the same age randomly selected from the general population were interviewed. Women who consumed alcoholic beverages had no greater risk of breast cancer than non-drinkers (relative risk 1.0, 95% confidence interval 0.8--1.2). Breast-cancer risk was not associated with the average amount of alcohol consumed per week nor with the type of alcoholic beverage consumed. Compared with non-drinkers, the relative risks of breast cancer for women who ever drank beer, wine, or spirits were 1.0, 0.8, and 0.9, respectively.

Risk factors for complications of interval tubal sterilization by laparotomy

The complication rate among 282 women undergoing interval tubal sterilization by laparotomy was studied as part of the prospective multicenter Collaborative Review of Sterilization. Using a standard definition of major complications, the overall complication rate was 5.7 per 100 procedures. Women experiencing complications had a significantly lengthened postoperative recovery period before the resumption of normal activities. Important risk factors for complications included diabetes, cigarette smoking, previous abdominal or pelvic surgery, and a history of pelvic inflammatory disease. Women with an initial abdominal incision of 7 cm or longer had three times the complication rate of women with shorter incisions. These results provide objective evidence that, for tubal sterilizations, minilaparotomy (laparotomy with a small abdominal incision) is associated with lower morbidity than is conventional laparotomy.

Type of intrauterine device and the risk of pelvic inflammatory disease

To study the association of pelvic inflammatory disease and various types of intrauterine devices (IUDs), data from the Women's Health Study were analyzed. The analysis included data from interviews of 622 women hospitalized with an initial episode of pelvic inflammatory disease and 2369 hospitalized control subjects reporting no history of pelvic inflammatory disease. Compared to the risk in women using no contraception, the relative risk of pelvic inflammatory disease in women currently using the Dalkon Shield was 8.3 (95% confidence limits 4.7 to 14.5). This represented a fivefold increase in risk compared to women currently using other types of IUDs. In this study, only 10% of women wearing an IUD were using the Dalkon Shield, yet they accounted for almost 20% of the excess risk of pelvic inflammatory disease occurring among all the IUD users. Most of the increased risk of pelvic inflammatory disease for women currently using other IUDs (excluding the Dalkon Shield) occurred in the first four months after insertion. These associations were not explained by differences between cases and controls in demographic variables, level of sexual activity, or medical history. The authors recommend that women still using a Dalkon Shield have it removed.

Deaths attributable to tubal sterilization in the United States, 1977 to 1981

In 1979, the Centers for Disease Control began surveillance of deaths attributable to tubal sterilization in order to determine why they occur and what may be done to prevent them. Since that time, 29 such deaths have been identified as occurring in the United States from 1977 through 1981. Of these 29 deaths, 11 followed complications of general anesthesia, seven were due to sepsis, four were due to hemorrhage, three were due to myocardial infarction, and four deaths were related to other causes. Some of these deaths might have been prevented by use of endotracheal intubation for general anesthesia, particularly for laparoscopic sterilization, safer use of unipolar coagulation or use of alternative techniques, careful insertion of the needle and trocar for laparoscopy, and discontinuation of oral contraceptives before sterilization. Further surveillance may help to make tubal sterilization even safer.

Risk of wound and pelvic infection after laparoscopic tubal sterilization: instrument disinfection versus sterilization

To determine if disinfection, rather than sterilization, of laparoscopic equipment leads to an increase in the risk of postlaparoscopy infection, the authors analyzed data from a multicenter prospective study conducted by the Centers for Disease Control on the safety of sterilizing operations. From September 1978 through July 1981, 3903 women underwent laparoscopic tubal sterilization procedures in which the equipment was sterilized with ethylene oxide (58%) or disinfected with glutaraldehyde (42%). The overall risk of wound infection in each group was 1.5 per 100 women. The relative risk of wound infection for disinfection versus sterilization of the equipment was 0.5 when adjusted for differences in the two groups. The corresponding relative risk of pelvic infection was 1.2. These results suggest that laparoscopy equipment disinfected with glutaraldehyde is not associated with an increased risk of wound or pelvic infection compared with equipment sterilized with ethylene oxide.

The safety and efficacy of tubal sterilization: an international overview

This article presents a synthesis of some of the major published studies on the efficacy and safety of tubal sterilization. The conclusions of this overview are that tubal sterilization is a safe operation, long-term sequelae of tubal sterilization have not been well documented, and the risk of pregnancy following tubal sterilization is less than 1 in 100. Continued study is needed to determine how to make a safe and effective procedure even safer and more effective.

Ectopic pregnancy in the United States 1970 through 1978

Trends of the incidence and mortality associated with ectopic pregnancy (EP) in the United States were examined for 1970 through 1978. The estimated number of EPs rose from 17,800 in 1970 to 42,400 in 1978, and the EP incidence rate rose from 4.5 per 1,000 reported pregnancies to 9.4 during the same time period. The risk of EP was higher for older women and nonwhite women. Over 2.5% of all reported pregnancies among nonwhite women aged 35 to 44 years were ectopic. The death-to-case rate for EP declined almost 75% during the study period but remained consistently higher for nonwhite women as compared with white women.

Mortality associated with fertility and fertility control: 1983

This analysis demonstrates that levels of mortality associated with all major methods of fertility control (tubal sterilization, the pill, IUD, condom, diaphragm, spermicides, rhythm and abortion) are low in comparison with the risk of death associated with childbirth and ectopic pregnancy when no fertility control method is used. The exceptions are the risks associated with pill use after the age of 40 for women who do not smoke, and with pill use after the age of 35 for smokers. The safest approach to fertility control is to use the condom and to back it up by abortion in case of method failure. Except for the lowest-risk method of fertility control (condom and abortion) and the highest (pill use by a smoker), most strategies of fertility control result in a similar risk of mortality until the woman reaches 35 years of age. At that point, risk from pill use rises more sharply than risk associated with other methods. The above conclusions are based on the lowest contraceptive failure rates reported by Schirm and his colleagues for married American women. If, instead, the highest failure rates are employed, use of the pill by a nonsmoker or the IUD clearly is safer than reliance on barrier methods or rhythm. As noted earlier, there are few women who make their contraceptive choices solely on the basis of perceived risk of mortality. Very few, for example, would consider abortion as a primary method of birth control; and for many, abortion would not be acceptable even as a backup for failed contraception. Although the risk of mortality resulting from use of the IUD is low, many women who have not yet had children might not want to face the increased risk of infertility problems from pelvic inflammatory disease that have been associated with use of this method.(ABSTRACT TRUNCATED AT 250 WORDS)

Agreement between women's histories of oral contraceptive use and physician records

The histories of oral contraceptive (OC) use provided by women participating in a study of hepatocellular adenoma (HCA) were compared with records obtained from their physicians. In the HCA study two memory aids were used to assist women in their recall: a calendar of significant events during a woman's lifetime to which she might relate her use of OCs and a book of colour photographs of the 90 OC preparations available up to the time of the study. Using the number of months of a woman's history which could be checked against physician records (mean for all women of 33 months) as the denominator, the highest proportion of concordance was for month-specific duration of OC use (90%) with lower agreement for duration and brand (62%) and duration, brand, and dose (54%). Agreement was better for cases than for controls.

Complications of abdominal and vaginal hysterectomy among women of reproductive age in the United States. The Collaborative Review of Sterilization

Although hysterectomy was the most frequently performed major surgical procedure among women of reproductive age during the past decade, few recent studies have been conducted to determine the risk of complications. We examined data from the Collaborative Review of Sterilization, a prospective, multicenter, observational study coordinated by the Centers for Disease Control, to assess the comparative risks of complications among women undergoing hysterectomy by the abdominal and vaginal approaches. Between September, 1978, and August, 1981, 1,851 women from nine institutions were included in the study. Women who underwent vaginal hysterectomy experienced significantly fewer complications than women who had undergone abdominal hysterectomy. The difference was probably attributable to the prevalence and efficacy of prophylactic antibiotic use among the former group. Vaginal hysterectomy was associated with more unintended major surgical procedures but less febrile morbidity, bleeding requiring transfusion, hospitalization, and convalescence than abdominal hysterectomy. Vaginal hysterectomy with prophylactic antibiotics should be strongly considered for those women of reproductive age for whom either surgical approach is clinically appropriate.

Oral contraceptives and pelvic inflammatory disease

To study the association of the use of oral contraceptives and pelvic inflammatory disease (PID), we analyzed data from a large multicenter case-control study of contraceptive use and serious gynecologic disorders. The analysis included data from interviews of 648 women hospitalized with an initial episode of PID and 2,516 hospitalized control subjects. The risk of PID for women using oral contraceptives in the 3 months prior to interview was 0.5 (95% confidence limits, 0.4 to 0.6) relative to women using no contraceptive method during this period. This association was not explained by differences between case subjects and control subjects in demographic variables, level of sexual activity, or medical history. The protective effect of current oral contraceptive use against PID was restricted to women using oral contraceptives for more than 12 months; past use of oral contraceptives did not exert a protective effect against PID. Annually, an estimated 50,000 initial cases of PID are prevented by oral contraceptive use; 12,500 hospitalizations are also averted by oral contraceptive use. Consequently, protection against PID is one of the most important noncontraceptive benefits of oral contraception.

Cumulative prevalence rates and corrected incidence rates of surgical sterilization among women in the United States, 1971--1978

The authors used data from the 1970 National Fertility Survey and Centers for Disease Control surveillance of surgical sterilizations to estimate the cumulative prevalences of hysterectomy and tubal sterilization among women of reproductive age in the United States between 1971 and 1978. In 1978, the cumulative prevalence rate of tubal sterilization was more than twice as high for women aged 15--44 years as it was in 1971 and at least three times as high for women under 30. Although the increase in the cumulative prevalence rate of hysterectomy was not as marked, by 1978, 19% of women aged 40--44 had undergone hysterectomy. The authors used the cumulative prevalence rate to estimate the population at risk for surgical sterilization, and calculated the corrected incidence rates for these procedures. While corrected incidence rates of tubal sterilization among women aged 15--44 doubled between 1971 and 1978, corrected hysterectomy rates remained stable. The largest age-specific increase in incidence rates of tubal sterilization was among women 40--44, with rates six times higher in 1978 than in 1971. These findings can be used to recompute incidence rates of endometrial and cervical cancers, abortions, and ectopic pregnancies, allowing more precise analysis of related trends.

Hysterectomy among women of reproductive age. Trends in the United States, 1970-1978

An estimated 3.5 million women aged 15 to 44 years in the United States underwent hysterectomy (excluding radical procedures) between 1970 and 1978. Data from the National Center for Health Statistics were used to study the influence of age, race, and geographic region on hysterectomy rates, surgical approach, and concurrent oophorectomy. The number and rate of hysterectomies increased between 1970 and 1972 but remained stable thereafter. Hysterectomy rates increased with age, and rates for black women slightly exceeded the rates for whites. Rates were consistently highest for women in the South and lowest for women in the Northeast. Women undergoing hysterectomy in the Northeast had the lowest percentage performed by a vaginal approach and the highest percentage performed in conjunction with bilateral oophorectomy. Women having a hysterectomy in the West had the highest percentage performed by a vaginal approach.

Barrier-method contraceptives and pelvic inflammatory disease

The protective effect of barrier-method contraception against pelvic inflammatory disease (PID) was examined by analyzing data from the Women's Health Study, a large multicenter case-control study. We compared the contraceptive methods used by 645 women hospitalized for initial episodes of PID with the contraceptive methods used by 2,509 control subjects reporting no history of PID. The risk of hospitalization for PID in women currently using barrier methods relative to women using all other methods and to women using no method of contraception was 0.6 (95% confidence limits, 0.5 to 0.9) for both comparisons. This protective effect was observed for both chemical and mechanical barrier methods, although it was not statistically significant for the former. The prevention of PID and its sequelae is one of the most important noncontraceptive benefits of barrier methods of contraception.

Deaths associated with laparoscopic sterilization in the United States, 1977-79

In 1979, the Centers for Disease Control began epidemiologic surveillance of deaths associated with tubal sterilization as part of an effort to assess the mortality risks associated with different methods of fertility control. The surveillance system identified nine deaths following laparoscopic sterilization in the United States from 1977 through 1979. The causes of these deaths and how some of them might have been averted are discussed.

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.

Demographic trends in tubal sterilization: United States, 1970-1978

In the period 1970-1977, an estimated 4,236,000 women 15-44 years of age had tubal sterilization operations in United States hospitals. Both the number and the rate of tubal sterilizations increased each year from 1970-1977, but in 1978 both declined. Tubal sterilization rates for Black women were higher than for White women. Black women also tended to be younger at the time of tubal sterilization. For the nation as a whole, the mean age at the time of tubal sterilization remained constant at about 30 with the youngest age group having the highest proportion of never-married women.

Death following puncture of the aorta during laparoscopic sterilization

Lacerations of major vessels have been associated with use of the Veress needle and sharp trocar for laparoscopy. A death caused by puncture of the aorta during insertion of a Veress needle is reported. Deaths from major vessel laceration can be prevented by using proper technique for inserting the needle and trocar or choosing alternative methods of sterilization that do not require these instruments. Should major vessel laceration occur, prompt recognition and treatment may prevent death.

The impact of laparoscopy on tubal sterilization in United States hospitals, 1970 and 1975 to 1978

During the 1970s, tubal sterilization became an important method of fertility control in the United States. Over the same period laparoscopy emerged as an important innovation, one that has been associated with both a shift from postpartum to interval sterilization and a dramatic decrease in length of hospital stay required for sterilization. The use of laparoscopy has also been associated with an increase in hospital-based outpatient sterilization, particularly in the West. The number of sterilizations performed in hospitals and the use of laparoscopy for interval sterilization in hospitals both appear to have peaked. The laparoscope is an example of a technologic advance that has reduced medical care costs.

The declining length of hospitalization for tubal sterilization

We analyzed factors affecting the length of hospital stay for tubal sterilization in 1970 and 1975, using data from the National Center for Health Statistic's Hospital Discharge Survey. The average hospital stay for tubal sterilization declined from 6.5 nights in 1970 to 4.0 nights in 1975. Pregnancy status, region of residence, and race were important determinants of the length of hospital stay. One technological innovation, the use of the laparoscope for tubal sterilization, accounted for 39% of the total length-of-stay reduction from 1970 to 1975. General changes in medical care from 1970 to 1975, combined with the introduction of laparoscopy, averted 1,363,000 nights of hospitalization for tubal sterilization in 1975. Conservatively, this resulted in a savings of more than $200 million. About $80 million of this savings was directly attributable to laparoscopy. Even greater savings could have been achieved if sterilization techniques requiring shorter hospital stays had been more widely used.

Ectopic pregnancy and intrauterine contraceptive devices: new perspectives. The Women's Health Study

In the period 1965 through 1977 the number of ectopic pregnancies in the United States tripled. A collaborative multicenter case-control study was set up to examine ectopic pregnancy as well as several other suspected complications related to use of an intrauterine contraceptive device (IUD). To determine to what extent IUD use might be related to this increase, the authors analyzed 615 women who had had an ectopic pregnancy and 3453 controls. Most important, women who had never used an IUD were equally likely to have an ectopic pregnancy as women who had used an IUD. Looking at the comparative risks for current contraceptive users, all current users, including IUD users, were less likely to have had an ectopic pregnancy than women not currently using contraceptives. Likelihood of ectopic pregnancy was the same regardless of whether a copper-containing or an inert plastic IUD was used. Among current IUD users, those who had used an IUD for a long time (25 months or more) were 2.6 times as likely to have had an ectopic pregnancy as short-term (less than 25 months) users. This difference between long- and short-term IUD users persisted for some time (not longer than 1 year) after removal of the IUD. Use of the IUD probably did not play a role in the recent tripling of ectopic pregnancies in the United States.

Deaths associated with laparoscopic sterilization by unipolar electrocoagulating devices, 1978 and 1979

In 1978 and 1979, two women in the United States were reported to have died from electrical complications following sterilization with unipolar coagulating devices. Both deaths followed apparent bowel injuries occurring at the time of sterilization. Numerous reports have documented the electrical accidents associated with unipolar electrocoagulation. Because unipolar electrocoagulation has greater risk for these complications than alternative sterilization techniques, without proved greater benefits, we question the need for continuing its use in female sterilization.

Ethinyl estradiol and conjugated estrogens as postcoital contraceptives

Five study centers enrolled 1,311 women seeking postcoital contraception methods. Ethinyl estradiol was administered at 5 mg/day and conjugated estrogens at 30 mg/day for five consecutive days starting within 72 hours of unprotected coitus. Eleven pregnancies occurred in the 976 women who had a single unprotected coitus at midcycle. Based on published information, 69 pregnancies would have been expected if no contraceptives were used. Although both treatments were effective in preventing pregnancy, ethinyl estradiol seemed to be more effective. At the two centers alternately prescribing both drugs, none of 137 women treated with ethinyl estradiol became pregnant, while six of the 132 given conjugated estrogens became pregnant. Women whose treatment commenced on the first postcoital day seemed to have lower pregnancy rates than those whose medication was delayed to the second or third postcoital day regardless of which drug was used. Side effects were mainly limited to nausea that occurred in 70% and vomiting that was experienced by 33% of all women treated.

Demographic trends of tubal sterilization in the United States 1970-75

An estimated 2,300,000 women in the United States underwent tubal sterilizations in 1970-1975. During this period the rate of tubal sterilizations per 1,000 women 15-44 years of age rose from 4.7 to 11.7. We studied the influence on sterilization trends of four demographic variables: age, region of residence, race, and marital status. Women 25-34 years of age were twice as likely to be sterilized as older or younger women. Rates were about 40 per cent lower in the West than in the rest of the country. In 1970 rates for non-white women were double those for Whites. Rates for Whites rose faster than those for non-Whites, however, and by 1975 the rates were similar for the 2 races. Non-Whites still tended to be sterilized about one year younger than Whites, and marked regional differences existed in the race-specific rate trends. Rates rose more sharply for previously married women than for currently married women; by 1975 rates for these two groups were similar. Never married women had rates about 1/7 of those of currently married and previously married women. Among the never married, tubal sterilization rates for non-Whites were nine times higher than those for Whites.