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Biomedical subjects

J M Samet

Publications and source records attributed to J M Samet.

At least 253 records · Page 14Linked to original sources
PubMed1985

Lung cancer risk and vitamin A consumption in New Mexico.

The association between dietary intake of vitamin A and lung cancer risk was examined in a population-based, case-control study of 447 patients and 759 control subjects in New Mexico. A food frequency interview was used to measure usual consumption of total vitamin A retinol, preformed vitamin A, and carotene. With all respondents combined, the odds ratios for lung cancer increased as intakes of total vitamin A and carotene declined but did not vary with intake of preformed vitamin A. When the subjects were stratified by ethnic group, Hispanic or non-Hispanic (Anglo) white, significant effects of vitamin A consumption were limited to the Anglos. In the Anglos, the protective effects of total vitamin A and carotene consumption were present in males and females, but varied strongly with cigarette smoking habits. In Anglo smokers, significant increases in the odds ratios with declining intake were observed in former but not in current smokers. Among the former smokers, significant effects of total vitamin A and carotene consumption were present only in those who had stopped smoking for 6 to 15 yr. Limitation of the protective effect of vitamin A and carotene consumption to past smokers has important implications for the design of clinical trials and for cancer control strategies.

Aged↗
PubMed1985

Cigarette smoking and health.

Cigarette smoking is the major preventable cause of increased mortality and premature disability in the United States. Smoking is a proven cause of coronary heart disease, chronic bronchitis and emphysema, and lung and other cancers. Maternal smoking is associated with low infant birth weight, increased perinatal mortality, and several complications of pregnancy. Passive smoking is associated with increased incidence of lower respiratory tract infections in very young children and may increase the risk of lung cancer in the nonsmoker. Smoking cessation is difficult because of nicotine addiction and psychological and social factors. Physicians and other health professions must be active both in helping people quit smoking and in preventing nonsmokers from starting. We recommend a national effort focused on preventing young people from starting to smoke.

Cardiovascular Diseases↗
PubMed1985

Cigarette smoking and lung cancer in 'Hispanic' whites and other whites in New Mexico.

A population-based case-control study of lung cancer was performed in New Mexico to explain the differing patterns of lung cancer occurrence in the state's "Hispanic" Whites and other Whites. From 1980 through 1982, interviews were completed with 521 cases and 769 controls. In the male controls, the prevalence of current and previous cigarette usage was similar in the two ethnic groups, but Hispanics smoked fewer cigarettes daily. In the female controls, a lower percentage of Hispanics had ever smoked and their usual consumption was less than that of other White women. Older Hispanic female smokers had used hand-rolled cigarettes for an average of 8.8 years, whereas other White women of the same age had used this type for less than one-half year. Both stratified and multiple logistic analysis showed comparable risks of lung cancer in Hispanic White and other White smokers. There was no evidence of interaction between ethnicity and cigarette smoking. These analyses imply that the differences in lung cancer incidence between New Mexico's Hispanic Whites and other Whites are largely explained by the patterns of cigarette smoking of these two groups.

Adult↗
PubMed1984

Uranium mining and lung cancer in Navajo men.

We performed a population-based case-control study to examine the association between uranium mining and lung cancer in Navajo men, a predominantly nonsmoking population. The 32 cases included all those occurring among Navajo men between 1969 and 1982, as ascertained by the New Mexico Tumor Registry. For each case in a Navajo man, two controls with nonrespiratory cancer were selected. Of the 32 Navajo patients, 72 per cent had been employed as uranium miners, whereas no controls had documented experience in this industry. The lower 95 per cent confidence limit for the relative risk of lung cancer associated with uranium mining was 14.4. Information on cigarette smoking was available for 21 of the 23 affected uranium miners; eight were nonsmokers and median consumption by the remainder was one to three cigarettes daily. These results demonstrate that in a rural nonsmoking population most of the lung cancer may be attributable to one hazardous occupation.

Adult↗
PubMed1984

Comparison of self- and surrogate-reported dietary information.

Studies of diet's role in the etiology of rapidly fatal diseases may utilize data taken from surrogate sources. To assess such sources, 46 subject-spouse pairs were interviewed with a food frequency questionnaire designed to provide an index of vitamin A consumption. Information concerning amount and past pattern of use was also obtained. The frequency and amount information was used to calculate two aggregate indices of vitamin A consumption: one based on frequency alone and the other based on frequency and amount. For single foods, the mean frequencies of consumption reported by subjects and by their spouses for them were similar; for both sexes combined, the average level of exact agreement was 66 per cent, with improvement to 93 per cent for agreement within one category. Similar agreement was found for amount. For the overall daily vitamin A intake of men, the means based on subject data were not significantly different from those calculated from their wives' responses. For women, husbands underreported their total intake. Agreement between subject- and surrogate-based overall vitamin A consumption was less satisfactory than for the individual foods.

Adult↗
PubMed1984

Alternatives in the collection and analysis of food frequency interview data.

In addition to frequency of consumption, a food frequency questionnaire may assess amount consumed, often by using food models, and the stability of diet. A food frequency interview directed at preformed vitamin A and beta-carotene was administered to 130 cases and 309 controls in an ongoing population-based case-control study of lung cancer in New Mexico. The questionnaire measured frequency, amount, and stability of consumption for 55 food items. Different combinations of responses to these three types of questions were used to calculate indices of total vitamin A consumption. The index based on frequency alone had the lowest value and increased significantly when amount was combined with frequency. Consideration of past consumption had relatively little effect on absolute and relative estimates of intake. Spearman rank order correlations between index pairs were high. These results suggest that the use of frequency alone is appropriate when the objective of data collection is to establish subjects' relative intake of specific nutrients.

Adult↗
PubMed1984

Prevalence survey of respiratory abnormalities in New Mexico uranium miners.

To obtain additional data concerning uranium mining and nonmalignant respiratory diseases, we conducted a prevalence survey of 192 long-term New Mexico uranium miners. Survey procedures included spirometry, completion of a respiratory symptoms questionnaire, physical examination and interpretation of available chest x rays. Total duration of underground uranium mining was used as the exposure index. Of the major respiratory symptoms, only the prevalence of dyspnea increased significantly with duration of uranium mining. With linear multiple-regression analysis, small but statistically significant effects of mining were found for two spirometric parameters, the forced expiratory volume in one sec and the maximal midexpiratory flow. By the 1980 International Labor Organization (ILO) U/C classification, 12 of 143 participants with x rays available for interpretation had at least category 1/0 pneumoconiosis. The opacities were predominantly nodular and compatible with silicosis.

Adult↗
PubMed1984

Risk factors for childhood respiratory disease. Analysis of pulmonary function.

Four thousand elementary-school-age children from a rural area of western Pennsylvania participated in a cross-sectional survey that consisted of a standardized respiratory questionnaire completed by their parents and spirometric testing at school. Spirographic tracings were digitized to obtain the FVC, FEV0.75, FEF25-75, Vmax75, and Vmax90, which were standardized for height, age, and sex for the subsequent analyses. Independent associations of potential risk factors with the standardized pulmonary function measures were evaluated with multiple regression techniques. Asthma, persistent wheeze, and parental smoking habits, especially those of the mothers, were associated with lower flow rates. The effect of parental smoking was primarily due to smoking by the mother and was stronger in girls. In female children of currently smoking mothers, FEF25-75 was 96% of predicted, Vmax75 was 95% of predicted, and Vmax90 was 92% of predicted; each flow measure was 98% of predicted in male children of smoking mothers. Prolonged hospitalization at birth was independently associated with lower FEV0.75 and flow rates. Low socioeconomic status was associated with lower FVC and FEV0.75. Neither current gas stove use nor a history of severe chest illness before 2 yr of age were independently associated with lower levels of pulmonary function.

Adolescent↗
PubMed1983

A tracking system for conducting epidemiological case-control studies.

The automated-respondent tracking system (ARTS) is an event-driven management system developed to monitor data collection during large epidemiological case-control studies. ARTS facilitates the conduct and management of these studies by eliminating the problems and limitations of manually monitoring subjects. This system, developed on an IBM 3032, consists of a series of programs linked by a general update program. Data captured on each subject for every study phase are used to generate lists of subjects requiring further action by the study staff. Additionally, ARTS produces reports reflecting a study's progress. Improved study management and reduced clerical load justify the system's costs. Concepts and programming principles applied to ARTS can be generalized to other epidemiological study designs.

Computers↗
PubMed1983

Survey research in New Mexico Hispanics: some methodological issues.

A prevalence survey of respiratory diseases was conducted in Albuquerque, New Mexico, with the objective of explaining differing patterns of respiratory disease epidemiology in Hispanic and non-Hispanic whites (Anglos). The study population was selected at random from the 1978 R.L. Polk & Co. Directory. This paper focuses on methodological issues raised during the conduct of the study: response rates, potential language barriers and bias, and identification of Hispanics by surnames. Mail, telephone, and personal interview approaches were used to obtain adequate response rates, which ranged from 60% in Hispanic males to 78% in Anglo females; 22% of Hispanic males refused interview. Fewer Hispanics returned mailed questionnaires than responded to telephone interviewing. Spanish language was increasingly preferred as the respondent's age increased. Two methods of ethnic identification by surname (1980 Census List of Spanish Surnames and a computer program, GUESS (Generally Useful Ethnic Search System) were compared to the self-reported ethnicity of respondents. The GUESS Program was more sensitive than the census list, but the census list was more specific. The combination of both methods produced a 90% sensitivity and 97% specificity in males. Intermarriage reduced the accuracy in females.

Adult↗
PubMed1983

The relationship between respiratory illness in childhood and chronic air-flow obstruction in adulthood.

This review evaluates the hypothesis that lower respiratory infection in childhood is a risk factor for chronic air-flow obstruction (CAO) in adulthood. Clinical CAO appears to result from a lengthy and initially asymptomatic loss of function that correlates with the development of peripheral airways abnormalities and emphysema. The relative functional silence of the small airways, the apparent vulnerability of the child's lung to injury, and the demonstration of functional abnormalities after several types of viral respiratory infection are consistent with the proposed role of lower respiratory infection. Relevant epidemiologic studies, however, have provided conflicting results, and many are flawed by recall bias. The observed association in children between lower respiratory infection and impaired ventilatory function may be noncausal and not a direct consequence of infection. A complete test of the hypothesis would require follow-up of study subjects from birth to adulthood with monitoring of respiratory infections and pulmonary function.

Adolescent↗
PubMed1983

Risk factors for childhood respiratory disease. The effect of host factors and home environmental exposures.

Standardized respiratory disease questionnaires (ATS-DLD-78-C) were completed by the parents of 4,071 children 5 to 14 yr of age, and risk factors for respiratory symptoms were evaluated by logistic analysis. Younger age, male sex, and lower socioeconomic status (SES) were independent risk factors for most respiratory symptoms and illnesses. All respiratory outcomes were significantly more prevalent in children with a physician's diagnosis of asthma. Asthma was more prevalent in male (4.5%) than in female (2.6%) children, and the greater prevalence of most respiratory symptoms in males did not persist in children with the same asthma status. Children whose questionnaires were completed by their fathers were reported to have significantly fewer respiratory symptoms than children with mother-completed questionnaires. We postulate that fathers underreport symptoms for their children. A positive parental history of allergy or respiratory illness was an independent predictor of respiratory symptoms and illnesses in the children. Chest illness before 2 yr of age and chest illness in the past year showed a significant positive linear trend with the number of parental smokers, and these effects of passive smoking were confirmed in the logistic analysis. The use of gas cooking stoves, inversely associated with SES, was not an independent risk factor for any respiratory symptoms or illnesses.

Adolescent↗
PubMed1983

Early and late pulmonary complications of botulism.

Pulmonary complications of botulism were studied in an outbreak of 34 cases of type A botulism in New Mexico in 1978. Hospital record review, standardized questionnaires, and pulmonary function tests were used to define pulmonary complications during the acute illness and the patient's status one year later. Pulmonary involvement was documented in 81% of patients. Ventilatory failure occurred in 11, aspiration pneumonia in nine, and death in two patients. Difficulties in the diagnosis of ventilatory insufficiency were identified. At one year, most patients had residual symptoms, including easy fatigability in 68% and exertional dyspnea in 46%. However, only minor pulmonary function abnormalities were present. This study confirms the generally favorable prognosis of botulism and provides clinical guidance for the diagnosis and management of pulmonary complications in botulism.

Adolescent↗
PubMed1982

Malignant melanoma of the skin in New Mexico 1969-1977.

We assessed the occurrence of malignant melanoma of the skin in New Mexico from 1969-1977. Incidence data, collected by the New Mexico Tumor Registry, were supplemented with mortality data supplied by the State Bureau of Vital Statistics. These data were analyzed for variation by site, sex, and ethnic group. Malignant melanoma occurrence varied with ethnicity. Incidence rates for non-Hispanic whites (Anglos) exceeded comparison US rates, and were approximately six times higher than for other ethnic groups. Annual incidence rates for Hispanics, American Indians, and blacks of both sexes ranged from 0.0-1.8 cases per 100,000. As anticipated from other studies, the lower extremities were the most common site in Anglo women, and the trunk was the most common site in Anglo men. In contrast, the trunk was the most common site for both Hispanic men and women. A statistically significant trend of increasing incidence was demonstrated only for the Anglo women. Mortality rates varied widely during the study period and did not correlate with incidence rates.

Adolescent↗