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Biomedical subjects

B Rosner

Publications and source records attributed to B Rosner.

At least 307 records · Page 17Linked to original sources
PubMed1982

On the estimation and testing of interclass correlations: the general case of multiple replicates for each variable.

Methods have recently been developed for the estimation and testing of mother-child correlations. In this report, these methods are extended to the general case of assessing interclass correlations where multiple replicates are allowed for each of the two classes of individuals under consideration. An algorithm is presented for obtaining the maximal likelihood estimator and an asymptotic test of significance is provided. In addition, a computationally convenient significance test is derived based on the pairwise estimator whereby one estimates the effective number of degrees of freedom in a family as a function of the number of replicates and the estimated intraclass correlation for each of the two types of individuals and sums up the effective degrees of freedom over all families in the sample. These methods are shown to be applicable to more general situations than the analysis of familial data, including the assessment of correlations between two variables measured at one point in time or the same variable measured at two points in time.

Biometry↗
PubMed1982

Factors in predicting blood pressure change.

A total of 1166 male participants (ages 23--80 years) of the Normative Aging Study who had baseline blood pressure less than 140/90 mm Hg were followed prospectively for 10 years. Blood pressures were taken at 5- and 10-year follow-up examinations. Multiple linear regression analysis indicated that baseline levels of systolic pressure, hematocrit, subscapular skinfold thickness and age were significant predictors of systolic pressure change during the follow-up period. Baseline levels of diastolic pressure, hematocrit, and body mass index were significant predictors of diastolic pressure change. Multiple logistic regression analysis revealed that only baseline blood pressure and hematocrit were significant predictors of subsequent blood pressure elevation to more than 159 mm Hg systolic or 94 mm Hg diastolic. Although the mechanisms by which hematocrit and body build affect blood pressure are unknown, these results suggest that identifying hypertension-prone subjects and delaying or preventing hypertension may be possible.

Adult↗
PubMed1982

Changes in cholesterol and triglyceride as predictors of ischemic heart disease in men.

We examined the relation of longitudinal changes in cholesterol and triglyceride to the subsequent development of heart disease. The data were from 1437 participants of the Normative Aging Study, a prospective study of men from the Boston area who were free of ischemic heart disease on two examinations approximately 5 years apart. Forty-four had symptoms or ECG findings of ischemic heart disease after their second but before their third examination, a period of 3-5 years. The risk of heart disease was studied using a multiple logistic risk model that took into account smoking and other risk factors. Changes in cholesterol and triglyceride levels between Exams 1 and 2, when corrected for regression to the mean, were better predictors of heart disease incurred between Exams 2 and 3 than initial levels of cholesterol, triglyceride or systolic blood pressure. When two age groups (28-52 years and 53-85 years) were considered, changes were important predictors in each age group. These findings suggest the importance of monitoring lipid changes over time.

Adult↗
PubMed1982

The effect of occupational exposure on pulmonary function: a longitudinal evaluation of fire fighters and nonfire fighters.

To examine the chronic effect of fire fighting on pulmonary function, we undertook a longitudinal analysis of 168 fire fighters and 1,474 nonfire fighters enrolled in a study of normal aging. Spirometric measurements (FVC and FEV1) were obtained on all subjects over a 5-yr intake period (1963 to 1968) and these subjects were reexamined 5 yr later (1968 to 1973). Questionnaire information about smoking habits, respiratory symptoms, and illness was also obtained. Fire fighters had a greater loss of pulmonary function (FVC and FEV1) than nonfire fighters (p = 0.007 and p = 0.054). This occupational effect could not be explained by differences in age, height, smoking status, or initial level of pulmonary function between the two occupational groups. Although respiratory symptoms were greater among current cigarette smokers, they were not significantly different between either occupational group. However, fire fighters generally reported more symptoms when smoking was controlled for. These results confirm earlier reports of a chronic effect of fire fighting on pulmonary function and suggest an association of this occupational with increased respiratory symptoms and disease independent of cigarette smoke.

Adult↗
PubMed1982

A two year trial of low protein, low arginine diets or vitamin B6 for patients with gyrate atrophy.

Four patients with gyrate atrophy on low protein (20-35 g/day), low arginine diets and one on vitamin B6 (300 mgm/day) have maintained their plasma ornithine concentrations in the range of 30-60% of pre-therapeutic trial levels for about two years. After two years, three of the five patients have shown no significant change in Snellen visual acuity, visual fields, final dark-adapted thresholds or full-field electroretinograms. All five patients have shown slight enlargement of areas of chorioretinal atrophy in the midperiphery. These patients continue on low protein, low arginine diets or on vitamin B6 to determine whether any reduction in the hyperornithinemia will result in stabilization of retinal function.

Adolescent↗
PubMed1982

Oral contraceptive use and malignant melanoma.

There was no overall relationship between a prior history of oral contraceptive (OC) use and the development of melanoma among 141 cases of nonfatal malignant melanoma and 2,820 age-matched controls drawn from respondents to a large postal survey of registered U.S. nurses; crude relative risk (RR) was 0.93 and 95% confidence limits (CL) were between 0.64 and 1.36. Adjustment for a number of additional variables did not alter this estimate materially. Duration of OC use and interval since first use were similarly unrelated to the occurrence of melanoma. For women diagnosed before age 40, there was a crude positive association of "ever" use of OC and melanoma (RR = 1.78; 95% CL, 1.11-2.86). However, adjustment for geography and other variables diminished this association and rendered it statistically not significant (RR = 1.43, 95% CL, 0.83-2.46). These data do not support the hypothesis that OC use is an independent risk factor for melanoma.

Adult↗
PubMed1982

Statistical methods in ophthalmology: an adjustment for the intraclass correlation between eyes.

For the cases of normally- and binomially-distributed outcome variables, methods are presented for analyzing ophthalmologic data to which a person may have contributed two eyes worth of information, the values from the two eyes being highly correlated. A frequently-used method of analysis, where each eye is treated as an independent random variable, is shown to be invalid in the presence of intraclass correlation: it yields true p-values two to six times as large as nominal p-values when realistic assumptions are made about the degree of correlation between eyes. These results may be applicable to other medical specialties, such as otolaryngology, where highly-correlated replicate observations are obtained from individuals.

Analysis of Variance↗
PubMed1981

Oral contraceptives and risk of ovarian cancer.

Among a large cohort of married, female, registered nurses under 55 years of age, oral contraceptive (OC) use was examined in women with ovarian cancer and 470 age-matched controls. Use of OCs before the diagnosis of cancer was reported by 28% of the women with ovarian cancer and 33% of the controls, yielding a relative risk of 0.8 (95% confidence limits 0.4-1.5). This apparent inverse relationship was attributable to a large effect in women 35 years of age or younger (relative risk = 0.2, 95% confidence limits 0.1-1.0). Patients with ovarian cancer were 2.2 times more likely than controls to be nulliparous. These data provide reassurance that OC use is not likely to be associated with any major increase in risk of ovarian cancer, but suggest that future studies of this relationship need to consider the possible confounding effect of infertility.

Adult↗
PubMed1981

Sexually transmitted conditions among women college students.

We studied 500 unselected young women who consulted a gynecologist in a student health service. Most participants were symptom-free and had normal physical examinations. Few sexually transmitted infections were encountered. Neisseria gonorrhoeae was recovered from two and Trichomonas vaginalis was obtained from 14 of 500 women. Chlamydia trachomatis was recovered from 20 (4.6%) of 439 participants. Genital warts, genital herpes, and molluscum contagiosum, respectively, were noted in seven, four, and one of the 500 participants. There was no cases of syphilis, scabies, or pediculosis pubis. Mycoplasma hominis and Ureaplasma urealyticum, respectively, were recovered from 17.6 and 56.8% of the subjects. Prevalent vaginal bacteria included lactobacilli, streptococci, Staphylococcus epidermidis, and diphtheroids. Gardnerella vaginalis was isolated from the vaginal specimens of about one third of the participants.

Adolescent↗
PubMed1981

Early menopause and the risk of myocardial infarction.

We evaluated the relation between age at menopause and the risk of nonfatal myocardial infarction (MI) among 121,964 nurses who responded to a mail questionnaire. Of 279 women who reported having been hospitalized for MI, 123 (44%) were postmenopausal (i.e., no longer menstruating) at the time of hospitalization, compared with 1,859 (33%) of 5,580 age-matched control subjects. Among women who became menopausal because of bilateral oophorectomy, the estimated relative risk of MI increased with decreasing age at menopause, and women who underwent bilateral oophorectomy before age 35 were estimated to have a risk of hospitalization for MI approximately 7.2 times (95% confidence interval, 4.5 to 11.4) that of premenopausal women. Hysterectomy without the removal of both ovaries was only weakly associated with an increased risk. The data support the hypothesis that premature cessation of ovarian function increases the risk of nonfatal MI.

Adult↗
PubMed1981

Vitamin supplement use among registered nurses.

A dietary questionnaire which included items relating to the use of specific vitamin preparations was sent to a randomly selected group of 2000 female, registered nurses aged 30 to 59 yr residing in 10 states. Among the 1742 women (87%) who returned completed questionnaires, the rates of use were 38% for multiple vitamins, 4% for specific preparations of vitamin A, 23% for vitamin C, and 15% for vitamin E. Women who used specific preparations of vitamins A, C, and E generally consumed them in quantities many times greater than the RDA. Use of specific vitamin preparations was found to increase with age and was highest in California.

Adult↗
PubMed1981

Cigarette smoking and non-fatal myocardial infarction in women.

The relationship between smoking and the risk of hospitalization for acute myocardial infarction (MI) was evaluated among 121,964 nurses and aged 30-55 years who resided in 11 of the larger US states and who responded to a mail questionnaire. Among 249 women who experienced an MI, 159 (64%) were smokers at the time of hospitalization. Of 4977 controls matched to the cases on the basis of age, 1850 (37%) were smoking at the corresponding time. Smokers experienced a three-fold increase in risk of MI relative to individuals who never smoked, which was not explained by history of hypertension, diabetes, high cholesterol or familial MI. Women who had stopped smoking experienced a risk of MI no greater than women who had never smoked.

Adult↗
PubMed1981

Early age at first birth and decreased risk of breast cancer.

The relationship between age at birth of a first child and breast cancer was evaluated for 1159 affected women and 11,590 women without cancer in data collected in 1976 among married female registered nurses residing in 11 states in the United States. A positive trend of increasing risk of breast cancer with later ages at first birth was found (chi 2(1) for trend in proportions = 30.9, p less than 0.01). Adjustment for potential confounding variables by multiple logistic regression did not affect this trend. The presence of this relationship using non-hospitalized controls of similar social status to cases supports the reality of this association, which has recently been challenged as an artifact due to inappropriate choice of hospitalized controls.

Adult↗
PubMed1981

Use of postmenopausal hormones and risk of myocardial infarction.

Information was collected by mail survey about myocardial infarction (MI), use of female hormones after menopause, and coronary risk factors 121,964 registered nurses ages 30-55 years. One hundred twenty-three women with a known type of prior menopause reported hospitalization for MI. Overall, use of female hormones by these women was very similar to that of control women matched for age and type of menopause. Compared with nonusers, the relative risk (RR) for women who had ever taken female hormones was 0.9 (95% confidence limits 0.6-1.2), and for current users the RR was 0.7 (0.5-1.1). For women with bilateral oophorectomy, the RR for current users was 0.4 (0.2-0.8). These data imply that, at present, a decision to prescribe postmenopausal hormones should be based primarily on weighing possible benefits from the relief of menopausal symptoms against unknown or suspected risks of other diseases, particularly uterine cancer in women with an intact uterus.

Adult↗
PubMed1981

Relative mortality of unbelted infant passengers and belted non-infant passengers in air accidents with survivors.

Aircraft accidents with survivors were examined to determine the relative risk of mortality for unrestrained infant passengers vs seat-belted adult passengers. The crude relative risk was estimated to be 7.1, based on US data, and 7.4, based on worldwide data. More refined estimates allow for possible effect of seat location and for differences in lethality between crashes. Using such estimates, unbelted infant passengers have relative risk of 5.9 based on US data and 9.6 based on worldwide data. The injury experience of restrained vs unrestrained automobile passengers suggests that observed excess risk to infant air passengers may be related to the absence of a mechanical restraint system. Recommendations for a mechanical restraint system are made and the cost and benefits of implementing these recommendations in the US are discussed.

Accidents, Aviation↗
PubMed1980

Infection with Mycoplasma hominis in postpartum fever.

A follow-up of 535 patients after vaginal delivery showed that 9% had a fever of 37.7 degrees C or greater, and 2% had a fever of 38 degrees C or more, on two days. The commonest cause of both categories of fever was Mycoplasma hominis infection as defined by a fourfold or greater rise in mycoplasmacidal antibody titre. Among women for whom sera were available this agent caused 50% (14/28) of all fevers and 71% (5/7) of the higher fevers. Absence or low titre (< 1:8) of antibody against M. hominis was the strongest single predictor of otherwise unexplained fever (16/40 patients with low antibody titre were febrile vs 7/50 with high antibody titre, p < 0.01). Among women with absent or low antibody titres, both rise in titre of antibody to this organism and lochial colonisation by it were significantly associated with fever (p < 0.001, p < 0.025, respectively). Standard microbiological and clinical techniques identified probable causes in only 18% (5/28) of all fevers and 29% (2/7) of higher fevers. Patients who had postpartum infection caused by M. hominis remained in hospital 31% longer than the non-infected patients (4.57 vs 3.49 days, p < 0.001). Low antibody to and lochial colonisation with M. hominis occurred together in 17% of patients, who accounted for 71% of all higher fevers. Since these risk factors for postpartum fever can be identified before delivery, prophylactic measures applied selectively to women with these risk factors may prevent a large proportion of postpartum fevers and the excess hospital stay associated with them.

Adult↗