Oral contraceptive use and fibrocystic breast disease among pre- and postmenopausal women

The association between use of oral contraceptives and fibrocystic breast disease was assessed among women aged 20-74 years in a hospital-based case-control study conducted between November 1979 and November 1981 in Connecticut. The study groups comprised 633 women with biopsy-proven fibrocystic breast disease and 1,062 controls who had been admitted, as inpatients or outpatients, to general surgical services. For the premenopausal women, there was no evidence that long-term use of oral contraceptives was associated with a decreased frequency of fibrocystic breast disease among either current or past users. For the postmenopausal women, previous oral contraceptive exposure was associated with an increased occurrence of cystic disease. These findings contradict previous investigations reporting a negative association between oral contraceptive use and the development of fibrocystic breast disease.

Epidemiology of musculoskeletal impairments and associated disability

Data from the US Health and Nutrition Examination Survey (HANES I) of 1971-1975 confirm the high prevalence of musculoskeletal impairments among United States adults. Musculoskeletal impairments tend to be more prevalent among older persons, and persons with less education and with lower annual family incomes. Prevalence rates are slightly higher in females than in males, while Whites and non-Whites are affected with almost equal frequency. Among persons reporting a history of musculoskeletal symptoms, those who have some disability tend to be older, non-White, of lower education and income, and widowed, separated, or divorced. Persons with multiple parts of the body involved, or reporting that their symptoms are due to accident or injury are also especially likely to report disability. Taken as a whole, the data suggest that medical, social, and economic factors all play a role in determining whether a person with musculoskeletal impairment goes on to develop disability related to his or her impairment.

Caffeine consumption and fibrocystic breast disease: a case-control epidemiologic study

In a hospital-based case-control study that included 634 women with fibrocystic breast disease and 1,066 comparison women in Connecticut, the occurrence of fibrocystic breast disease was positively associated with average daily consumption of caffeine. Women who consumed 31-250 mg of caffeine/day had a 1.5-fold increase in the odds of disease, whereas women who drank over 500 mg/day had a 2.3-fold increase in the odds. The association with caffeine consumption was especially high among women with atypical lobular hyperplasia and with sclerosing adenosis with concomitant papillomatosis or papillary hyperplasia, both of which have been associated with an increased breast cancer risk. The association was specific to fibrocystic breast disease in that there was no association of caffeine consumption with fibroadenoma or other forms of benign breast disease.

An epidemiologic study of lifting and twisting on the job and risk for acute prolapsed lumbar intervertebral disc

An epidemiologic case-control study undertaken in Connecticut during 1979-1981 indicated that persons with jobs requiring lifting objects of more than 11.3 kg (25 lb) an average of more than 25 times per day had over three times the risk for acute prolapsed lumbar intervertebral disc as people whose jobs did not involve lifting objects of this weight. If the body was usually twisted while the lifting was done, this elevation in risk was apparent with less frequent lifting. An especially high risk for prolapsed lumbar disc was associated with jobs involving lifting objects of more than 11.3 kg with the body usually twisted and the knees not bent while the lifting was done. Neither lifting objects of less than 11.3 kg nor twisting without lifting was associated with an increase in risk.

Cohort studies

Cohort studies generally provide more definitive evidence regarding causality than do other types of observational epidemiologic studies, but the high cost usually associated with them limits their use to special situations. Retrospective cohort studies and combined cohort/case-control studies are suggested as modifications of the traditional prospective cohort study which retain certain of their advantages but which are considerably less expensive.

Physical activity and the risk of spontaneous preterm delivery

An epidemiologic case-control study exploring possible risk factors for preterm delivery was undertaken at Yale-New Haven Hospital during 1977. The study groups consisted of 175 mothers of singleton preterm infants and 313 mothers of singleton term infants. Analysis of questionnaire responses provided no evidence that employment, housework, child care and leisure-time physical activity during pregnancy increased the risk of preterm delivery. Women who participated in sports or physical fitness exercises during pregnancy were found to have a significantly decreased risk of preterm delivery as compared to those who were not similarly active; this finding suggests that certain forms of moderate physical activity may actually protect against preterm delivery.

Oral contraceptive use and fibrocystic breast disease with special reference to its histopathology

The relationship between use of oral contraceptives and fibrocystic breast disease was examined in a hospital-based case-control study undertaken in New Haven, Connecticut, from 1977 to 1979. Particular emphasis was placed on the extent of epithelial atypia and other histopathologic characteristics found in the biopsy specimens from the cases. Women who had ever used oral contraceptives were at a somewhat decreased risk for fibrocystic disease as a whole. Cases with high atypia and controls had similar patterns of oral contraceptive use, whereas cases with low and intermediate atypia had less oral contraceptive use than controls. Cases with intermediate atypia reported the lowest oral contraceptive use. Subjects with biopsy specimens exhibiting gross cysts, microscopic cysts, or papillomatosis were about 50% less likely to have used oral contraceptives than controls.

Differences in breast cancer risk factors according to the estrogen receptor level of the tumor

One hundred and forty-eight postmenopausal breast cancer cases and 585 postmenopausal controls were included in an investigation of whether various risk factors for breast cancer are associated with the level of estrogen (E) receptor (ER) protein in the tumor. In an intracase analysis, the tumor ER level was positively associated with nulliparity, late age at first live birth, a history of benign breast disease, and having breast-fed at least 1 child and was negatively associated with previous use of E replacement therapy. A case-control analysis suggested that the first three variables, established risk factors for breast cancer, are associated with an increased risk for malignant breast tumors that are ER-positive but not for those that are ER-negative. This analysis did not provide a clear interpretation of the findings in the intracase comparisons with regard to prior breast-feeding and the use of E replacement therapy.

Cost and efficiency in the choice of matched and unmatched case-control study designs

This study compares matched and unmatched case-control designs in terms of the precision with which one can estimate an exposure-disease association while controlling for the effects of a confounding variable. Provision is made for the cost of the matching process by calculating the reduction in the number of controls that can be studied for fixed study cost. The purpose is to provide epidemiologists with guidelines and quantitative procedures for making rational decisions as to which is the more appropriate study design for specific research problems. The results indicate that when the cost of the matching process is negligible, a matched design is usually more efficient than an unmatched one. The difference in efficiency is generally slight, however, and is found to depend primarily on the strength of the confounder-disease association, the prevalence of exposure, and the strength of the exposure-disease association. When the cost of the matching process is not negligible, a matched design is likely to be less efficient than an unmatched one.

A case-control study of cancer of the endometrium

A hospital-based case-control study of the epidemiology of endometrial cancer in women aged 45-74 years was carried out in Connecticut from 1977 to 1979. In total, 167 cases and 903 controls were included. Elevated risks were associated with the following factors: overweight, nulliparity, few pregnancies, use of estrogen replacement therapy, older age at menopause, and a history of ovarian or endometrial cancer in mother or a sister. Whites were more frequently affected than blacks, and better-educated women more often than less-educated women. Use of oral contraceptives was associated with a decreased risk, although the decrease did not reach statistical significance.

An epidemiologic study of hip fracture in postmenopausal women

In this case-control study of the epidemiology of hip fracture in post-menopausal women aged 45-74 years, cases of hip fracture and two control groups were selected from admissions to four general hospitals in Connecticut between September 1977 and May 1979. Fewer cases of hip fracture than controls had been exposed to estrogen replacement therapy, and among those who had been exposed, exposure time was shorter than that for controls. The cases had breastfed their children for shorter durations, and they more often had had both ovaries removed. Also, the cases were found to weigh less than the controls. The negative associations of hip fracture with estrogen replacement therapy, intact ovaries, and weight are consistent with the hypothesis that estrogens protect against hip fracture.

Effect of age at first childbirth on risk of developing specific histologic subtype of breast cancer

Epidemiologic variables related to breast cancer risk were assessed in a case-control study of 332 women with breast carcinoma and 1353 comparison women. Risk factors for breast cancer as a whole included nulliparity, late age at first childbirth, early age at menarche, late age at menopause, personal history of benign breast disease, family history of breast cancer, and among postmenopausal women, body weight. These risk factors were then analyzed with respect to histologic subtype of breast cancer involved, i.e., duct-derived or lobular tumors, to determine whether the association between any of the risk factors and breast cancer varied according to histopathologic subtype. Histologic subtype for the 316 cases reviewed included 284 duct cancers and 32 lobular carcinomas. Although slight differences were noted among some of the risk factors and the variety of cancer, none of the differences was marked except for the variable age at birth birth. For ductal carcinoma, the risk was highest among nulliparous women and decreased the younger a woman was at the time she gave birth to her first child. The risk of infiltrating lobular carcinoma, however, was lowest among nulliparous females or those who had given birth at a young age and increased the older a woman was when she gave birth to her first child.

An epidemiologic study of epithelial carcinoma of the ovary

A case-control study to identify risk factors for epithelial ovarian cancer was undertaken among women in the age group 45-74 years who had been admitted to seven hospitals in Connecticut between July, 1977, and March, 1979. Characteristics that were found to increase the risk of epithelial ovarian cancer included being white, never having been pregnant, having a late age at menopause, having a family history of cancer of the ovary or endometrium, and having a long estimated number of years of ovulation. Prior use of post-menopausal estrogens did not alter the risk for epithelial ovarian cancer, but there was some indication that oral contraceptives protect against ovarian cancer. Women with ovarian cancer were somewhat more likely to have had a history of an underactive thyroid and were somewhat less likely to have had a history of an overactive thyroid than controls, although these trends were not statistically significant.

Exogenous estrogens and other factors in the epidemiology of breast cancer

In a hospital-based case-control study of the epidemiology of breast cancer undertaken in Connecticut from 1977 to 1979, there was no evidence of an increase in risk for breast cancer among women who had used oral contraceptives or estrogen-replacement therapy. In fact, there was some suggestion of a decrease in risk for breast cancer with increasing length of use of oral contraceptives. Higher than average risks were found among women who had never give birth to a child, women with a late age at menopause, women, with an early age at menarche, women who had given birth to their first child at a relatively late age, women with previous benign breast disease, and women with a history of breast cancer in a sister or mother. Heavy women were at high risk for premenopausal breast cancer. The association between heaviness and postmenopausal breast cancer was strongest among women who had had their last menstrual period more than 5 years before the diagnosis of breast cancer.

Injuries to the upper extremity: patterns of occurrence

Injuries to the upper extremity, as reported in home interviews, physician office records, and hospital records, are a problem of great magnitude. Upper extremity injuries not only are responsible for a great deal of disability and for a large number of visits for medical care, but also, because they often affect people of working age, have a great impact on society because of loss of productivity. However, regardless of the age at which they occur, these injuries can have an impact on the quality of life of the injured, both in the short term and in the long.

Epidemiology and impact of low-back pain

Disorders of the lumbar spine are among the most common medical problems in western countries, affecting up to 80% of people at some time during their lives. The epidemiology and impact of six specific disorders of the lumbar spine are reviewed. These include prolapsed discs, disc degeneration, osteoarthrosis of the apophyseal joints, fractures and dislocations of vertebrae, osteoporosis, and spondylolisthesis. Various mechanical factors contribute to the causation of most of these disorders, but other underlying pathologic mechanisms are important as well. In light of the great impact of these conditions on society and on individuals, it is concluded that there is a considerable need for a greater allocation of resources for improvement in methods of prevention, diagnosis, and treatment.

Fibroadenoma in oral contraceptive users: a histopathologic evaluation of epithelial atypia

We have reviewed histologically a series of 120 fibroadenomas which formed part of the case material from a previous case-control epidemiological investigation of the relationship between oral contraceptive use and breast disease. We evaluated the epithelial component of the fibroadenoma for degree of cytologic atypia. This study indicates that the reduced risk for fibroadenoma among long-term users of oral contraceptives does not vary according to the degree of epithelial atypia present. This is in contrast to our previously reported findings for fibrocystic disease, in which the decreased frequency of occurrence of the disease in long-term users of oral contraceptives was found only for cases with no minimal epithelial atypia.

The impact of musculoskeletal disorders on the population of the United States

Musculoskeletal disorders constitute such a large component of impairments of individuals in the working and geriatric population that good statistical data on them are essential for planning health care. We have collected the pertinent data, with references to recent source material, to determine the incidence, effect on the quality of life, and associated costs of these disorders in the United States.

Role of oral contraception in congenital malformations of offspring

In a case control study we examined the relationship between congenital malformations in offspring and maternal exposure to oral contraceptives around the time of conception. There were 1 370 with congenital malformations and 2 968 healthy control infants. Maternal oral contraceptive use was unrelated to malformations considered as a whole whether exposure last occurred in the year before conception [odds ratio = 0.9, p=0.25] or during pregnancy [odds ratio = 1.3, p=0.30]. Exposure during pregnancy doubled the risk for some specific diagnoses, including certain cardiovascular defects, but these increases were not statistically significant. Exposure to specific oestrogens or progestogens was also unrelated to the occurrence of malformations. There was a suggestion that women who both smoked more than 20 cigarettes per day and used oral contraceptives during pregnancy were more likely to deliver a malformed infant than were women who neither used oral contraceptives nor smoked during pregnancy.

Fibrocystic breast disease in oral-contraceptive users. A histopathological evaluation of epithelial atypia

Epidemiological studies show a lower frequency of fibrocystic breast disease among long-term users of oral contraceptives than among women who have never used them. Fibrocystic disease may be a precursor of breast cancer; yet the incidence of breast cancer does not appear to differ between pill-takers and nontakers. To resolve this conflict, we examined the problem from a histologic standpoint in 205 premenopausal women, and found that this decreased frequency applied only to fibrocystic disease in which epithelial atypia was minimal or absent. In women with marked atypia there was no significant difference in frequency among long-term users as compared to women who have never used oral contraceptives. These findings suggest that a spectrum of cystic disease exists and that the long-term use of oral contraceptives protects against the forms of fibrocystic disease that are not firmly associated with an increased risk of breast cancer, but not against the premalignant forms.

Maternal smoking and congenital malformations: an epidemiological study

In a case-control study undertaken in several hospitals in Connecticut, it was found that women who reported smoking more than 20 cigarettes a day during pregnancy had a relative risk of about 1.6 for congenital malformations in the offspring of that pregnancy compared with women who said they had not smoked at all during pregnancy. However, there was no significant increase in risk among women who reported smoking 20 or fewer cigarettes a day during pregnancy compared with those who said they had not smoked at all during pregnancy. The higher risk among moderate and heavy smokers could not be attributed to any of the potentially confounding variables considered in this study; furthermore, it was specific to smoking during pregnancy rather than before pregnancy, and increased with the average amount smoked a day. Nevertheless, because the increase in risk was modest, because response bias could exist in a study of this type, and because no other studies have examined in detail the smoking-congenital malformation hypothesis, further research is needed to determine whether the relationship between maternal smoking and congenital malformations in offspring is causal.

Oral contraceptives and breast disease. An epidemiological study

A case-control study of the relationship between use of oral contraceptives and cancer of the breast, cancer of the corpus uteri, cancer of the ovary, and benign breast diseases was undertaken among women in the age group 20--44 years who had been admitted to several large hospitals in Connecticut. No significant association was seen between use of oral contraceptives and breast cancer. It was found that the longer a woman had used sequential oral contraceptives, the lower her relative risk of benign breast disease. Use of combination oral contraceptives, however, did not appear to influence the risk of benign breast diseases. The numbers of cases with cancer of the ovary and of the corpus uteri in this age group were too small for any conclusions to be reached.