Vaginal spermicides and congenital disorders.

Among 763 liveborn infants of white women who had obtained a vaginal spermicide in the ten months before conception, the prevalence of certain major congenital anomalies was 2.2%. The prevalence of such anomalies in a comparison group of 3,902 infants was 1.0%. The difference between these groups was due to an excess of limb-reduction deformities, neoplasms, syndromes associated with chromosomal abnormalities, and hypospadias in the infants whose mothers are presumed to have used vaginal spermicides. Pregnancies in women who had used vaginal spermicides ended in spontaneous abortion requiring hospitalization 1.8 times more commonly than did pregnancies in those who had not. Since a well-defined syndrome among babies with congenital disorders whose mothers used spermicides was not present, these results should be considered tentative until confirmed by other data.

Vasectomy and non-fatal myocardial infarction.

The incidence of non-fatal myocardial infarction among 4830 vasectomised men was 0.9 cases per 1000 man-years during 24 420 man-years of observation. This was slightly lower than the rate in 24 150 non-vasectomised men, matched with a vasectomised man for calendar year of birth and duration of observation. Review of medical records for a matched sample of study subjects indicated no measurable confounding by important cardiac risk factors.

PIP: This study was undertaken to investigate the risk of nonfatal myocardial infarction among vasectomized men. Among a group of 4830 vasectoized men there were 23 first time infarctions, giving a rate of 0.90 infarction/1000 man-years at risk. There were 120 first time infarctions in a control group of nonvasectomized men, giving a rate of 1.0 infarctions/1000 man-years at risk. Incidence rate rose with time in both groups as the men became older, and obesity and smoking were both associated with infarction in both groups. The lack of a vasectomy-related effect was present throughout an observation period of 7 years after vasectomy. Some laboratory data gathered on monkeys suggest that there may be long-term risks not yet manifested in human populations. Long-term studies are needed to obtain more information on the subject.

Oral contraceptives and breast cancer.

The incidence of breast cancer among users and non-users of oral contraceptives (OCs) was determined at Group Health Cooperative of Puget Sound, Seattle, Washington, a health care organization which maintains computer files of diagnoses and outpatient drug use. In women 45 years of age or younger, the incidence was nearly identical in users and non-users. In premenopausal women over 45 years of age, there was a positive association between current OC use and breast cancer, the risk ratio estimates and 90% confidence intervals being 4.0 (1.8-9.0) in women 46-50 years of age and 15.5 (5.2-46) in women 51-55 years of age.

PIP: A study on the possible effect of (OCs) oral contraceptives on breast cancer risk was conducted at the Group Health Cooperative of Puget Sound in Seattle, Washington. Exposure and menopausal data were available on women and controls. Among the women aged 31-5, 20% used OCs during the period ending June 30, 1976 as compared with 13% 2 years later. For those women aged 51-5, user prevalence declined from 2% to 0.3%. 76 of 132 women with breast cancer were premenopausal and 4 were under 30 years of age. Estimates of breast cancer rates in the group of current OC users and nonusers were not adjusted for potential confounding by other risk factors; these were later assessed into a multiple logistic function. Those factors were: age, ponderal index, age at menarche, age at 1st pregnancy, history of benign breast disease, education, and race. Current OC use was entered into the risk function in the form of age-use interaction terms. 1 aspect of the case-control comparison which did not correspond to the population-based findings was the apparent protective effect of current OC use in the group ages 31-40. Among those currently using OCs, there is a preponderance of long-term users; no such trend exists among past users. Data from this study indicate that there may be a relation between OC use and breast cancer which is age dependent. Within the age group 31-45 years, the incidence in current users (0.71/1000 women-years) was nearly identical to nonusers (0.65/1000 women-years) however, current OC use was associated with a strong increase in breast cancer risk in premenopausal women 46-55 years. Other factors for which the breast cancer risk ratio may increase with age include pregnancy, and endocrine risk factor. Relationships previously noted which are included in these data include associations between risk and nulliparity, educational level, and slimness (for women who are premenopausal).

Replacement estrogens and breast cancer.

The relation between replacement estrogens and breast cancer in menopausal women (age 45-64 years) was evaluated in the Group Health Cooperative of Puget Sound, Washington State, a prepaid health care organization with fully computerized information on outpatient drug use and hospital diagnoses. Little association between current estrogen use and breast cancer was noted in women with a previous hysterectomy (relative risk (RR) = 1.1; 90% confidence interval (Cl), 0.7-1.8). In women with a natural menopause there was a positive association between current estrogen use and breast cancer (RR = 3.4; 90% Cl, 2.1-5.6). This association was strong in naturally menopausal women aged 45-54 years (RR = 10.2) and weaker in the older age group (RR = 1.9).

A comparison of surgical assisting in a prepaid group practice and a community hospital.

Previous studies of the work loads and time utilization of general surgeons in two different practice settings suggested that paraprofessional surgical assistants (SAs) could reduce surgeon assisting time and perhaps increase productivity. In order to further assess the potential advantage of using SAs as surgical assistants, the present study examines assisting patterns in a prepaid group practice where SAs are used and in a community hospital where only physicians are available to assist. In the prepaid group practice, 87 per cent of general surgical procedures were performed with an assistant; in the c ommunity hospital, 67 per cent of general surgical procedures were performed with an assistant. General practitioners also were found to assist in the community hospital; family practice residents, medical students and "others" also assisted in prepaid group. In both settings, the propensity to use an assistant was positively correlated with operative complexity. On operations of greatest complexity, surgeons were most likely to act as first assistants. The use of SAs was not usually associated with operative sessions longer than when surgeons assisted, except on operations of high complexity. In the prepaid group, SAs also frequently assisted on orthopedic surgery, neurosurgery and obstetrics-gynecology, only occasionally on otolaryngology and plastic surgery, and never on ophthalmology. It appears that in organizations such as a prepaid group practice, where mechanisms for sharing resources exist and incentives are provided to minimize the total cost of surgery, the utilization of SAs might be associated with cost savings. At present, organizational and financial barriers exist to the introduction of paraprofessionals as surgical assistants. It is difficult to advocate the modification of these barriers to facilitate the training and large-scale introduction of this new group of paraprofessionals in the current surgical market where there may already be an excess supply of surgeons.

Replacement estrogens and endometrial cancer.

We examined the incidence of endometrial cancer in a large prepaid group practice in the Seattle area. From July, 1975, to July, 1977, there was a sharp downward trend in the incidence of endometrial cancer that paralleled a substantial reduction in prescriptions for replacement estrogens. Incidence rates were estimated for estrogen users and nonusers among women 50 to 64 years of age with intact uteri; current long-term users had an annual risk for endometrial cancer between 1 and 3 per cent, whereas nonusers had a risk less than 1/10th as great. These incidence rates remained fairly constant over time among users and nonusers; the drop in overall incidence soon after estrogen use declined suggests that the increased risk associated with estrogens falls quickly after discontinuation. The reduction in incidence of endometrial cancer in this group practice was part of a general decline in the United States after 1975.

Time utilization of a population of general surgeons in a prepaid group practice.

Seven general surgeons in a prepaid group practice previously shown to have a mean operative work load of 9.2 hernia equivalents (HE) per week were found to have a standardized mean daytime working week of 56.2 hours, exclusive of evening activities of which 50.7 hours were devoted to professional activities. The surgeons also devoted a mean of 6.7 evening hours per week to professional activities for a mean net professional week of 57.4 hours. Comparisons with a population of previously studied community surgeons revealed that the prepaid group surgeons were able to produce a surgical output more than double that of the community surgeons while devoting only one and a half as much time to professional activities. Economies in the utilization of surgical manpower in the prepaid group appear to stem from: 1) restriction of practice setting to a single geographic location, 2) restriction of patients to surgical patients, 3) reduced surgeon waiting time in the office, and 4) the utilization of paraprofessional personnel for selected operative assisting. These economies were achieved while the prepaid group surgeons were observed to average more time per patient visit both on rounds and in the office than the community surgeons.