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Biomedical subjects

A Morabia

Publications and source records attributed to A Morabia.

At least 127 records · Page 7Linked to original sources
PubMed1993

Consistent lack of association between breast cancer and oral contraceptives using either hospital or neighborhood controls.

BACKGROUND: Case-control studies of oral contraceptive use and breast cancer have used neighborhood, population, or hospital controls. METHODS: To determine whether this association differs according to type of controls, interview data from 131 incident cases of breast cancer were compared with those of 189 hospital controls and 182 neighborhood controls Study subjects were white females recruited between 1973 and 1975 from among residents of Baltimore City and County ages 18 to 59 years. RESULTS: Adjusted relative odds of breast cancer related to ever versus never use of oral contraceptives were 1.0 and 0.8, using hospital and neighborhood controls, respectively. Relative odds did not increase proportionally to duration of oral contraceptive use or to progestogen potency. Although few subjects had used oral contraceptives for more than 2 years, almost all pill brands contained more than 49 micrograms of ethinyl estradiol or of mestranol. CONCLUSIONS: Results from the present study do not support the hypothesis that early preparations of oral contraceptives increased breast cancer risk among white women, regardless of whether controls are neighbors of the cases or hospital patients. However, its conclusions cannot be generalized to women who began taking the pill before their first full-term birth or took it for more than 2 years.

Adolescent↗
PubMed1993

[Dietary intake of total lipids and saturated fatty acids of the Geneva population: an unexpected development].

Results of two dietary surveys performed 10 years apart suggest that the Geneva population has a lower caloric intake and a lower proportion of total fat and saturated fat in the total caloric intake. These changes are observed in all ages, sexes or nationalities. They may indicate that prevention campaigns promoting a healthier diet with a lower content of calories and fat have had some impact. However, because of methodological differences between the two surveys we cannot conclude that these dietary changes are real.

Adult↗
PubMed1992

Relation of bronchioloalveolar carcinoma to tobacco.

OBJECTIVE: To determine whether bronchioalveolar carcinoma is related to tobacco use. DESIGN: Case-control study. SETTING: 11 teaching hospitals of Chicago, Long Island, New York, and Philadelphia, 1977-89. SUBJECTS: 87 patients with histologically diagnosed bronchioloalveolar carcinoma (cases) and 286 non-cancer and 297 cancer patients matched to cases on age, sex, race, hospital, and date of admission. RESULTS: 10% of male cases and 25% of female cases had never smoked. Relative risks of bronchioloalveolar carcinoma (as estimated by the relative odds) were greater for subjects who started smoking at a younger age, smoked for a longer time, or smoked more cigarettes per day. Relative risks decreased proportionally to the duration of smoking cessation. CONCLUSION: Smoking plays an important part in the aetiology of bronchioloalveolar carcinoma but is not the only potential cause because of the large proportion of never smokers among patients with this disease.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1992

Geographic variation in cancer incidence in the USSR: estimating the proportion of avoidable cancer.

BACKGROUND. The Soviet Union offers a unique frame in which to study geographic variation in cancer incidence because of its uniform registration system of all newly diagnosed cancer cases throughout its 15 republics and 162 oblasts (administrative units). Variation in cancer rates is stronger when examined by oblasts than it is when examined by republics. In 1986, the age-standardized all-site cancer incidence rate for both sexes, in the Soviet republic having the highest overall rate (Russian Soviet Federative Socialist Republic for males, Lithuania for females) was about twice that of the Soviet republic with the lowest all-site cancer rate (Georgia). Within Soviet oblasts (data are from 1979), the ratio of the highest to the lowest rates was about 4 for all sites, 144 for male oesophageal cancer, and 303 for female oesophageal cancer. The excess incidence in the entire USSR compared with the republic having the lowest all-site incidence rate was 59% for males and 49% for females. CONCLUSION. Although the observed differences between republics or between oblasts are partially due to uneven quality of data recording or to statistical variability related to population sizes, there is a strong geographic variation of cancer incidence rates in the USSR that suggests a potentially important role of environmental factors in cancer etiology.

Environment↗
PubMed1992

The influence of patient and physician gender on prescription of psychotropic drugs.

There is a wealth of evidence that more psychotropic drugs are prescribed to female than to male patients. We studied the psychotropic drug prescription of 15 male and 9 female physicians to 2493 patients in the Ambulatory Care Clinic of a University hospital. The relative odds (RO) of benzodiazepine prescription to a female compared to a male patient was the same when the physician was a male or a female (adjusted RO: 1.8; 95% CL: 1.5-2.1). But female patients were significantly more likely to be prescribed psychotropic drugs of all types from a female than from a male physician (adjusted RO: 1.3; 95% CL: 1.0-1.7). Information on patient diagnosis or on severity of symptoms would be needed to determine whether the present results reflect gender differences in medical care needs, overprescription of psychotropic drugs to females or underprescription of psychotropic drugs to males.

Attitude of Health Personnel↗
PubMed1992

Misclassification bias related to definition of menopausal status in case-control studies of breast cancer.

It is often assumed, but has not been consistently observed, that some characteristics of reproductive history are specifically related to breast cancer of pre- or postmenopausal onset. To determine whether inconsistent reports may be due to differences in definition of menopause, we computed the relative odds (RO) of breast cancer for nulliparity, age at first live birth, family history of breast cancer and prior history of benign breast disease, separately in pre- and postmenopausal women, using seven different definitions of menopause. Results show that (i) relative odds of breast cancer and their confidence intervals may vary according to definitions of menopause; (ii) age-based definitions of menopause are associated with moderate differential misclassification bias between cases and controls; (iii) nulliparity, late age at first birth and family history of breast cancer seem to be specific risk factors for pre- but not postmenopausal breast cancer when cutoff for menopausal status is 10 years or more after last menses; and (iv) when information on menstrual history is not available, 50 years of age may be the best proxy for all menses-based definitions of menopause. We conclude that inconsistent findings on the effect of menopausal status in the association of breast cancer with some reproductive factors are partly due to statistical imprecision and differential misclassification bias associated with different age-based or menses-based definitions of menopause. Researchers should either test whether their conclusions hold using several definitions of menopause or give a biological rationale for the choice of a given definition of menopause.

Age Factors↗
PubMed1992

Effect of occupational and recreational activity on the risk of colorectal cancer among males: a case-control study.

Epidemiological studies have consistently demonstrated that either occupational or recreational physical activity is protective against colon cancer. However, it is unclear whether recreational activity is similarly protective among those who engage in high or low occupational activity. We therefore compared 440 male cases of colorectal cancer with 1164 male hospital patients. Occupational activity was defined according to job title, while recreational activity was assessed by questionnaire for three different periods of life. Occupational activity was protective with respect to colorectal cancer irrespective of whether one engaged in recreational activity at any different period of life. In contrast, recreational activity, performed at 20-44 years of age appeared to decrease colon cancer risk by 10-25% irrespective of the intensity of job activity. The present results suggest that, although we observed a larger effect with occupational activity than with recreational activity, middle-aged men may reduce their risk of colorectal cancer if they exercise when they are not working. These findings need to be confirmed in other populations.

Adolescent↗
PubMed1992

Lung cancer and occupation: results of a multicentre case-control study.

The objective of the current study was to estimate the risk of lung cancer attributable to occupational factors and not due to tobacco. At 24 hospitals in nine metropolitan areas in the United States, 1793 male lung cancer cases were matched for race, age, hospital, year of interview, and cigarette smoking (never smoker, ex-smoker, smoker (1-19 and > or = 20 cigarettes per day)) to two types of controls (cancer and non-cancer hospital patients). Information on usual occupation, exposure to specific potential carcinogens, and cigarette smoking was obtained by interview. Risk of lung cancer was increased significantly for electricians; sheetmetal workers and tinsmiths; bookbinders and related printing trade workers; cranemen, derrickmen, and hoistmen; moulders, heat treaters, annealers and other heated metal workers; and construction labourers. All of these occupations are potentially exposed to known carcinogens. Odds ratios (ORs) were increased for exposure to coal dust (adjusted OR = 1.5; 95% confidence interval (95% CI) 1.1-2.1). After stratification, this association was statistically significant only after 10 or more years of exposure. Lung cancer was also related to exposure to asbestos (adjusted OR = 1.8; 95% CI 1.5-2.2). The ORs increased with increasing duration of exposure to asbestos for all smoking categories except for current smokers of 1-19 cigarettes per day. The statistical power to detect ORs among occupations that were previously reported to be at increased risk of lung cancer but that failed to show an OR of at least 1.5 in the current study was small. The cumulative population attributable risk (PAR) of lung cancer due to occupation was 9.2%. It is concluded that occupational factors play an important part in the development of lung cancer independently of cigarette smoking. Because occupations at high risk of lung cancer were under-represented, the cumulative PAR of the present study is likely to be an underestimate of the true contribution of occupation to risk of lung cancer.

Case-Control Studies↗
PubMed1992

Assessment of whole-body composition with dual-energy x-ray absorptiometry.

Dual-energy x-ray absorptiometry (DXA) allows noninvasive direct measurement of the three major components of body composition: lean body mass (LBM), fat body mass (FBM), and bone mineral body mass (BBM). To study the accuracy and short-term and long-term precision of body composition measurements, the authors measured body composition with DXA in 60 healthy young adults. Independent measurement of LBM (LBMK-40), obtained from the determination of the whole-body content of potassium-40 with a whole-body scintillation detector, was highly correlated with LBM determined with DXA (LBMDXA) (LBMK-40 = 1.069.LBMDXA,R2 = .996). Assessment of body composition in 10 patients with acquired immunodeficiency syndrome (AIDS) and 10 patients with cystic fibrosis was performed with DXA. The AIDS patients showed a marked decrease in LBM, while in patients with cystic fibrosis, LBM and BBM were decreased. DXA measurements of body composition appeared accurate and precise enough to be of clinical relevance in detecting specific alterations of body composition.

Absorptiometry, Photon↗
PubMed1991

Cigarette smoking and lung cancer cell types.

The role of tobacco smoke in the development of lung cancer is well known for squamous and small cell types, somewhat less so for adenocarcinoma, and not specifically assessed for large cell carcinoma. In the current analysis, based on 851 men and 507 women with lung cancer and their matched controls (888 men and 608 women), smoking was associated with each lung cancer cell type, and differences in smoking habits by cell types were small. However, the increase of lung cancer risk according to number of cigarettes per day was stronger for small cell and oat cell carcinoma than for adenocarcinoma. There was no increase for large cell carcinoma. For squamous cell carcinoma, this dose response was weak among men and strong among women. The strength of the association between smoking and lung cancer cell types may be related to cancer location, with more peripheral lung cancer types (such as adenocarcinoma and large cell carcinoma) showing weaker associations than more central tumors (such as squamous or small cell and oat cell carcinoma).

Adenocarcinoma↗
PubMed1991

On the origin of Hill's causal criteria.

The rules to assess causation formulated by the eighteenth century Scottish philosopher David Hume are compared to Sir Austin Bradford Hill's causal criteria. The strength of the analogy between Hume's rules and Hill's causal criteria suggests that, irrespective of whether Hume's work was known to Hill or Hill's predecessors, Hume's thinking expresses a point of view still widely shared by contemporary epidemiologists. The lack of systematic experimental proof to causal inferences in epidemiology may explain the analogy of Hume's and Hill's, as opposed to Popper's, logic.

Causality↗
PubMed1991

Comparison of smoking habits of blacks and whites in a case-control study.

Information from Blacks and Whites interviewed in a case-control study of tobacco-related diseases was analyzed to identify explanatory factors for racial differences in smoking habits. Blacks were three times more likely to be light vs heavy smokers. This association did not differ according to such variables as cigarette preference, degree of inhalation, or quitting. The association of race and light smoking was present in both current and ex-smokers. Sociodemographic or smoking-related characteristics do not appear to explain racial differences in smoking habits. Future studies should focus on cultural factors influencing smoking behavior.

Adult↗
PubMed1990

Epidemiology and natural history of breast cancer. Implications for the body weight-breast cancer controversy.

The mechanisms of differentiation of the mammary gland apparently can explain the contradictory findings on the association of breast cancer with excess body weight. Excess weight may be related to the initiation of breast cancer in premenopausal women through its effect on menstrual cycles and on progesterone secretion and to the promotion of breast cancer in postmenopausal women through its effect on estrogen metabolism. Although body weight is unlikely to be as strong a risk factor for breast cancer as it is for endometrial cancer, it may have a greater importance from a public health point of view, because the ratio of the incidence of breast cancer to that of endometrial cancer is 4.5 in whites and 6 in blacks. Thus, more studies seem warranted. It is not possible, however, to rule out the view that the reported correlation between excess weight and breast cancer is attributable to failure to adjust for potential confounders, such as dietary fat. New insights may come from the combined assessment of weight, different types of dietary fat, and reproductive history factors known to be involved in the natural history of breast cancer. For example, in the Women's Intervention Nutrition Study (WINS), the survival rate of breast cancer patients on a 20 per cent fat diet is being compared with that of breast cancer patients of similar weight keeping their usual 35 to 40 per cent fat diet. This investigation will show whether dietary fat influences the rate of progression (metastasis) and of promotion (occurrence of cancer in the other breast) independent of body weight.

Body Weight↗
PubMed1990

Pork intake and human papillomavirus-related disease.

Clinical and ecological evidence supporting an association between human papillomavirus (HPV)-related tumors and dietary factors are presented. Abstinence from high intake of fried pork (600-1,000 g/day) was associated with regression of an urethral condyloma in a healthy 19-year-old man treated with interferon gamma. International correlations suggest that pork intake is positively associated with incidence of cervical cancer, a disease also related to HPV. Pork meat or dietary factors associated with pork meat consumption may be involved in the development of HPV-related diseases.

Adult↗
PubMed1990

Dietary habits of smokers, people who never smoked, and exsmokers.

A large database on hospital patients with illnesses not related to tobacco or alcohol was used to investigate the dietary habits of males and females who never smoked, who were exsmokers, and who currently smoked. Smoking was positively related to meat consumption and negatively related to cereal consumption in males. Both male and female smokers consumed fewer vegetables and fruits but more alcohol and coffee than did people who never smoked. Exsmokers' diets were similar to those of people who never smoked. These results emphasize the importance of ruling out potential confounders or effect modifiers when studying the role of meat, milk, fruits, vegetables, cereal, coffee, or alcohol intake in the etiology of tobacco-related diseases.

Adult↗