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B V Stadel

Publications and source records attributed to B V Stadel.

At least 37 records · Page 2Linked to original sources
PubMed1987

Breast cancer risk in relation to type of estrogen contained in oral contraceptives.

We report analyses designed to address the recent hypothesis that women who use combination-type OCs containing ethinylestradiol (EE) are at increased risk of breast cancer before age 45, if use of such OCs occurs prior to first term pregnancy (FTP). Our findings, based on data from 1679 cases and 1689 controls, 20-44 years of age, from the population-based Cancer and Steroid Hormone Study, are against the hypothesis. The relative risk of breast cancer by duration of exclusive use prior to FTP of OCs containing EE is estimated to be 1.0 (1-12 months EE use), 1.2 (13-48 months EE use), and 0.9 (49+ months EE use). There was no evidence of a latent effect. Among parous women with 49+ months exclusive use prior to FTP of EE-containing OCs, the relative risk of breast cancer was estimated as 0.9 (0-4 years after FTP) and 0.6 (5-9 years after FTP). Among nulliparous women with 49+ months exclusive use of EE-containing OCs, the relative risk of breast cancer was estimated as 1.0 (0-4 years since first use), 0.7 (5-9 years since first use), and 1.1 (10-14 years since first use). With regard to exclusive use of OCs containing mestranol, parous women who used such preparations long-term before their FTP showed no alteration of breast cancer risk, even 15 years or more after pregnancy. Nulliparous women with exclusive use of ME-containing OCs did show elevations in breast cancer risk, but the magnitude of risk in relation to duration of use and latent interval shows no pattern that suggests a cause-effect relationship.

Adult↗
PubMed1987

Consistency and plausibility in epidemiologic analysis: application to breast cancer in relation to use of oral contraceptives.

Consistency and plausibility are fundamental criteria for judging cause and effect from observational studies. They are applied here to the interpretation of data from a population-based case-control study of oral contraceptives and breast cancer. A preliminary analysis of oral contraceptive use in young nulliparous women, who had no family history of either breast cancer or benign breast disease, showed a statistically significant dose-response, with long-term users (49 months or more) having an apparent 4-fold elevation in risk of early breast cancer. Further analyses, however, revealed striking inconsistencies which were biologically implausible. These effectively undermine cause and effect as an explanation for the initial finding.

Adult↗
PubMed1987

Exposure opportunity in epidemiologic studies.

We have shown that consideration of exposure opportunity is crucial to planning epidemiologic investigations because it focuses studies on questions of relevance, it helps to identify links to variables that can distort the assessment of an exposure's effect, and the cost of investigation can be reduced by the use of appropriate eligibility criteria. The reasons given by Poole for ignoring exposure opportunity are based on misleading claims of increased precision, disregard for probable confounding by factors related to exposure opportunity, and failure to consider realistically the cost of obtaining data on persons whose experience is irrelevant to the issues under investigation.

Contraceptives, Oral↗
PubMed1986

Appendectomy and the risk of tubal infertility.

We studied the importance of a history of appendectomy for appendicitis in 279 women with laparoscopically or surgically diagnosed tubal infertility and a control group of 957 fertile women. After controlling for the effects of age, use of an intrauterine device for contraception, a history of pelvic inflammatory disease, and other potential confounding variables, we found that no excess risk of tubal infertility was associated with a simple appendectomy without rupture. However, when the operation was reportedly for a ruptured appendix, the relative risk of tubal infertility was 4.8 (95 percent confidence interval, 1.5 to 14.9) for women who had never been pregnant and 3.2 (95 percent confidence interval, 1.1 to 9.6) for women with one or more previous pregnancies. We conclude that the early diagnosis and treatment of suspected appendicitis in girls and women of reproductive age may reduce the incidence of tubal infertility resulting from the sequelae of a ruptured appendix.

Adult↗
PubMed1986

The relation of endometriosis to menstrual characteristics, smoking, and exercise.

We compared menstrual characteristics and constitutional factors in 268 white women with primary infertility due to endometriosis and in 3,794 white women admitted for delivery at seven collaborating hospitals from 1981 to 1983. Adjusting for confounding factors, including location, age, religion, and education, women with short-cycle lengths (less than or equal to 27 days) and longer flow (greater than or equal to one week) had more than double the risk for endometriosis compared with women with longer cycle lengths and shorter duration of flow. There was a trend for increasing risk for endometriosis to be associated with increasing menstrual pain. Adjusting for these menstrual characteristics, we found decreased risk for endometriosis associated with smoking or exercise that was largely confined to women who began either habit at an early age and were heavier smokers or more strenuous exercisers. We conclude that risk for endometriosis may relate to menstrual factors that predispose to greater pelvic contamination with menstrual products and to constitutional factors that influence endogenous hormonal levels.

Adolescent↗
PubMed1985

Oral contraceptives and breast cancer in young women.

The relation between use of oral contraceptives (OCs) by young women and their risk of breast cancer before 45 years of age was investigated by analysis of data from a population-based, case-control study conducted in eight geographic regions of the United States. 2088 women with breast cancer diagnosed between Dec 1, 1980, and Dec 31, 1982, were compared with 2065 controls selected during the same period. There was no significant increase or decrease in the risk of breast cancer for OC users according to age at first use or subsequent duration of use, even for women who first used OCs before the age of 20 years and who continued to use them for more than 4 years. Risk was not altered significantly for women who used OCs with high progestagen "potency" before the age of 25 years (even when duration of use exceeded 6 years), for those who used OCs before first-term pregnancy (even when duration of use exceeded 4 years), or for OC users according to age at diagnosis. These results suggest that use of OCs by young women in the United States has no effect on the aggregate risk of breast cancer before 45 years of age.

Adult↗
PubMed1985

Primary tubal infertility in relation to the use of an intrauterine device.

Women who use an intrauterine device (IUD) are at increased risk of acute pelvic inflammatory disease, but the relation of the IUD to subsequent infertility is not established. We interviewed 159 nulligravid women with tubal infertility to determine their prior use of an IUD. Their responses were compared with those of a matched group who conceived their first child at the time the infertile women started trying to become pregnant. The risk of primary tubal infertility in women who had ever used an IUD was 2.6 times that in women who had never used one (95 per cent confidence interval, 1.3 to 5.2). The observed difference between cases and controls was not uniform for different types of IUD. The relative risk associated with use of a Dalkon Shield was 6.8 (1.8 to 25.2), and that associated with use of either a Lippes Loop or Saf-T Coil IUD was 3.2 (0.9 to 12.0). The smallest elevation in risk was found among users of copper-containing IUDs (relative risk, 1.9 [0.9 to 4.0] for all women who had ever used a copper-containing IUD). The relative risk for women who used only a copper-containing IUD was 1.3 (0.6 to 3.0). We conclude that use of the Dalkon Shield (and possibly of plastic IUDs other than those that contain copper) can lead to infertility in nulligravid women.

Adult↗
PubMed1985

Tubal infertility and the intrauterine device.

To study the association between intrauterine devices (IUDs) and pelvic inflammatory disease, we compared contraceptive histories in 4185 while women--283 nulliparous women with primary tubal infertility, 69 women with secondary tubal infertility, and 3833 women admitted for delivery at seven collaborating hospitals from 1981 to 1983. The relative risk of tubal infertility associated with IUD use was calculated by means of multivariate logistic regression to control for confounding factors, including region, year of menarche, religion, education, smoking, and reported number of sexual partners. The adjusted risk of primary tubal infertility associated with any IUD use before a first live birth was 2.0 (95 per cent confidence limits, 1.5 to 2.6) relative to nonuse. Users of the Dalkon Shield had an adjusted risk of 3.3 (1.7 to 6.1), users of the Lippes Loop or Saf-T-Coil had a risk of 2.9 (1.7 to 5.2), and users of copper IUDs had a risk of 1.6 (1.1 to 2.4). Women who reported having only one sexual partner had no increased risk of primary tubal infertility associated with IUD use. The adjusted risk of secondary tubal infertility associated with use of a copper IUD after a first live birth was not statistically significant (1.5; 95 per cent confidence limits, 0.8 to 3.0), whereas the risk from similar use of noncopper devices was significant (2.8; 1.3 to 5.9). We conclude that tubal infertility is associated with IUD use, but less so with copper IUDs.

Adult↗
PubMed1985

Tubal infertility in relation to prior induced abortion.

One hundred twenty-seven women who had been given diagnoses of tubal infertility between 1979 and 1981 in King County, Washington, yet previously had been pregnant, were interviewed to determine their prior history of legally induced abortion. Their responses were compared with those of 395 women who conceived a child at the same time the infertile women began their unsuccessful attempt to become pregnant. In making the comparison, we adjusted for the effects of variables that in this population were related both to having an induced abortion and to the occurrence of infertility, i.e., age, number of prior pregnancies, number of sexual partners, cigarette smoking habits, Dalkon Shield (A. H. Robins Company, Richmond, VA) use, and whether the woman worked outside the home. The risk of tubal infertility in women who had had an induced abortion was not increased above that of other women (relative risk, 1.15; 95% confidence interval, 0.70 to 1.89). For women with two or more abortions, the relative risk was 1.29 (95% confidence interval, 0.39 to 4.20). When only the most recent pregnancy was considered, the relative risk was 1.19 (95% confidence interval, 0.72 to 1.97). Our results suggest that legal abortion, as performed during the past decade in the United States, does not carry an excess risk for future tubal infertility.

Abortion, Induced↗
PubMed1984

Extent of surgery for pelvic inflammatory disease in relation to duration of intrauterine device use.

The risk of a first episode of pelvic inflammatory disease resulting in extensive surgery was examined in relation to duration of intrauterine device (IUD) use in a case-control study. Extensive surgery for pelvic inflammatory disease was defined as hysterectomy or bilateral adenexal surgery, with pelvic inflammatory disease as the only gynecologic discharge diagnosis. Of 690 hospitalized pelvic inflammatory disease patients with no prior history of the disease, 55 had extensive (requiring surgery) disease. These were compared to 2569 controls who were hospitalized with nongynecologic conditions. Current IUD users (within 30 days of admission) were considered to be long-term or short-term users, depending upon whether the same IUD had been used for five or more years or less than five years. Past IUD users and never-users were considered to be nonusers. For long-term users as compared to nonusers, the relative risk of extensive pelvic inflammatory disease was about 5.4; for short-term users as compared to nonusers, the relative risk was only about 1.4. Continuous use of the same IUD for five or more years appears to increase the risk of pelvic inflammatory disease, requiring extensive surgery to a greater extent than use for less than five years.

Adult↗
PubMed1981

Risk factors for fatal heart attack in young women.

Deaths of 338 women at ages 15-44 years attributed to myocardial infarction (MI) on death certificates during an 18-month period in five metropolitan areas were investigated. Evidence of recent MI or evidence that death occurred suddenly was obtained for about half (163) from records of hospitals or medical examiners or from relatives. A case-control study (involving one deceased control, and one hospitalized living control) of risk factors for heart attack was then conducted using interviews with relatives and abstracts of records of hospitals and physicians identified by the relatives as sources of medical care. Information was obtained on history of prior MI, other heart disease, diabetes, thromboembolism, stroke, hypertension, high cholesterol, obesity, oophorectomy, oral contraception and cigarette smoking. Data are presented on the prevalence of these potential risk factors for the case group and each control group, and for subsets of cases consisting of those without prior heart disease, definite MI only, sudden death only, and white women only. Multivariate analyses identify somewhat different sets of risk factors and different levels of risk for the various subgroups. In general, the risk factors are those that have been reported for men, despite the major difference in level of mortality.

Adolescent↗
PubMed1981

Cost of case-control studies.

A financial review of five case-control studies concerning the relationship of birth control methods to the occurrence of disease was conducted. The review had two major objectives: first, to identify costs associated with the planning, conduct and analysis of case-control studies; second, to assess whether sample size determination based on optimal allocation would have resulted in a significant reduction in cost. The data collection phase represented about 75% of the total cost of a study, whereas the costs of planning and analysis were roughly 10% and 15% of total cost, respectively. The typical cost in mid-1970s dollars was from +100-+200 per subject. Evaluation of an optimal allocation procedure based on the relative cost of cases and controls demonstrated that such a method was likely to reduce total study cost by at most 2 per cent.

Abnormalities, Drug-Induced↗