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Biomedical subjects

J M Samet

Publications and source records attributed to J M Samet.

At least 235 records · Page 13Linked to original sources

Epidemiologic approaches for the identification of asthma.

Clinical, physiologic, and questionnaire approaches can be used to identify subjects with asthma in an epidemiologic investigation. Each method, however, may select differing subsets of the population. At present, a comprehensive asthma questionnaire is unavailable; the difficulty of defining asthma in operational terms has been a major obstacle in the development of such a questionnaire. This review describes the questionnaires prepared by the British Medical Research Council and the American Thoracic Society and suggests modifications.

Asthma↗

Marriage to a smoker and lung cancer risk.

As part of a population-based case-control study of lung cancer in New Mexico, we have collected data on spouses' tobacco smoking habits and on-the-job exposure to asbestos. The present analyses include 609 cases and 781 controls with known passive and personal smoking status, of whom 28 were lifelong nonsmokers with lung cancer. While no effect of spouse cigarette smoking was found among current or former smokers, never smokers married to smokers had about a two-fold increased risk of lung cancer. Lung cancer risk in never smokers also increased with duration of exposure to a smoking spouse, but not with increasing number of cigarettes smoked per day by the spouse. Our findings are consistent with previous reports of elevated risk for lung cancer among never smokers living with a spouse who smokes cigarettes.

Aged↗

Cigarette use among Hispanic and non-Hispanic white school children, Albuquerque, New Mexico.

We conducted a survey of cigarette usage among Hispanic and non-Hispanic White school children in Albuquerque, New Mexico. The distributions of current, experimental, and never smokers were similar in the two groups. Among smokers, the average weekly cigarette consumption was 19 for Hispanic White males, 14 for non-Hispanic White males, 16 for non-Hispanic White females, and nine for Hispanic White females. Educational programs are needed to maintain the low-risk status of Southwestern Hispanics for cigarette-related diseases.

Adolescent↗

Daily air pollution effects on children's respiratory symptoms and peak expiratory flow.

To identify acute respiratory health effects associated with air pollution due to coal combustion, a subgroup of elementary school-aged children was selected from a large cross-sectional study and followed daily for eight months. Children were selected to obtain three equal-sized groups: one without respiratory symptoms, one with symptoms of persistent wheeze, and one with cough or phlegm production but without persistent wheeze. Parents completed a daily diary of symptoms from which illness constellations of upper respiratory illness (URI) and lower respiratory illness (LRI) and the symptom of wheeze were derived. Peak expiratory flow rate (PEFR) was measured daily for nine consecutive weeks during the eight-month study period. Maximum hourly concentrations of sulfur dioxide, nitrogen dioxide, ozone, and coefficient of haze for each 24-hour period, as well as minimum hourly temperature, were correlated with daily URI, LRI, wheeze, and PEFR using multiple regression models adjusting for illness occurrence or level of PEFR on the immediately preceding day. Respiratory illness on the preceding day was the most important predictor of current illness. A drop in temperature was associated with increased URI and LRI but not with increased wheeze or with a decrease in level of PEFR. No air pollutant was strongly associated with respiratory illness or with level of PEFR, either in the group of children as a whole, or in either of the symptomatic subgroups; the pollutant concentrations observed, however, were uniformly lower than current ambient air quality standards. Moreover, since exposure estimation based on monitoring of ambient air likely results in misclassification of the true exposure, the negative findings of this study must be interpreted cautiously.

Air Pollutants↗

Survival of American Indian and Hispanic cancer patients in New Mexico and Arizona, 1969-82.

Survival was examined by ethnic group for 31,465 incident cancer cases diagnosed from 1969 through 1982 in Hispanic and non-Hispanic whites residing in New Mexico and in American Indians residing in New Mexico and Arizona. In comparison with the 1- and 5-year survival rates following the diagnosis of cancer for non-Hispanic whites, those for American Indians were generally poorer and, to a lesser extent, those for Hispanics were also poorer. The American Indian and Hispanic patients tended to have more advanced disease at the time of diagnosis, although this pattern was not consistent across all sites. For many primary cancer sites, American Indian patients were less likely to receive treatment for their cancer than were non-Hispanic whites. Hispanics were also less likely to be treated for cancers of some sites, although the differences were not as large as for American Indians. However, after adjustment for stage and treatment, American Indians demonstrated significantly poorer survival than non-Hispanic whites for cancers of many sites. After adjustment for stage and treatment, survival in Hispanics was generally comparable to that in non-Hispanic whites.

Age Factors↗

Lung cancer and occupation in New Mexico.

The association between occupation and lung cancer risk was examined in a population-based, case-control study of 506 patients (333 males and 173 females) and 771 control (499 males and 272 females) subjects in New Mexico. A personal interview was used to obtain lifetime occupational and smoking histories and self-reported history of exposures to specific agents. High-risk jobs were identified in advance of data analysis and linked with industrial and occupational codes for hypothesis testing. For females, lung cancer risk was not associated with employment history, but power was limited. For males, elevated risks were found for the uranium mining industry [odds ratio (OR) = 1.9; 95% confidence internal (CI) = 0.8-4.9], underground miners (OR = 2.1; 95% CI = 1.1-3.7), painters (OR = 2.7; 95% CI = 0.8-8.9), and welders (OR = 3.2; 95% CI = 1.4-7.4). For self-reported exposure to any of 18 agents, only the OR for exposure to "other metals" was elevated. The population attributable risk in males was estimated as 14% for employment in any high-risk industry or occupation with an OR above 1 in this study.

Adult↗

Determinants of lung cancer risk in cigarette smokers in New Mexico.

Although cigarette smoking is the strongest known risk factor for lung cancer, the effects of specific smoking practices have not been completely characterized. The present study examines determinants of lung cancer risk in a population-based, case-control study conducted in New Mexico, 1980-82. The study included 521 cases and 769 controls matched for age, sex, and ethnicity. Either the index subjects or their next-of-kin were interviewed in person to obtain a detailed history of cigarette smoking and information concerning other risk factors. With the use of multiple logistic regression, a model was constructed of the effects of amount smoked, duration of smoking, cigarette type, and smoking cessation on lung cancer risk. Among current smokers, risk increased with each additional cigarette smoked per day (P less than .001). For duration of smoking, the risk per year smoked in individuals 65 years and older was only one-third that in persons under age 65 years. With regard to cigarette type, a somewhat higher risk was found associated with smoking nonfilter cigarettes, but there was no evidence of decreasing risk as the extent of filter smoking increased. Lifelong filter cigarette smokers and smokers of both filter and nonfilter cigarettes were at lower risk than lifelong smokers of nonfilter cigarettes only. In ex-smokers, the pattern of variation of relative risk with amount and duration was similar to that in the current smokers. Excluding those who had stopped for 1 year or less, the relative risk declined exponentially with duration of smoking cessation (P less than .01). These analyses confirm the strong benefits of smoking cessation and indicate possible reduction of risk from smoking filter cigarettes.

Adult↗

An assessment of the validity of questionnaire responses provided by a surviving spouse.

Studies of the etiology of rapidly fatal diseases often use data from surrogate sources. To assess the validity of the wife as a source of exposure information, 80 wives were interviewed in 1983-1984 for the same histories provided earlier by their husbands, who were cases in a case-control study of lung cancer in New Mexico, 1980-1982. Both interviews obtained detailed information concerning lifetime occupational history, smoking habits, and consumption of certain foods high in vitamin A. With regard to lifetime occupational histories, the wives reported significantly fewer jobs. Concordance of the coded histories was approximately 50% for occupation and industry, but was higher for the last job and usual job held. Wives correctly reported the cigarette smoking status of their husbands. For the number of cigarettes smoked per day, wives tended to report 20 cigarettes smoked even when their husbands smoked substantially more or less. The mean frequencies of consumption of certain food items based on the two sources were comparable. However, the percentage of exact agreement and the kappa statistics were generally low.

Aged↗

Stage at diagnosis of cancer varies with the age of the patient.

The stage of a cancer at diagnosis is multiply determined, theoretically depending on such disparate factors as tumor biology, patient education, and physician behaviors. Data from all Hispanic and non-Hispanic white residents of New Mexico diagnosed with a malignancy from 1969 through 1982 were analyzed to determine the relationship between the age of the patient and the stage of cancer at the time of diagnosis. Three general patterns were apparent. For cancers of the bladder, breast, cervix, ovary, thyroid, and uterus, and for melanoma, there were significant linear trends for the cancers to be diagnosed at more advanced stages in older patients. For cancers of the lung, pancreas, rectum, and stomach, there were significant linear trends for cancers to be diagnosed at an earlier stage in older patients. For cancers of the colon, kidney, liver, and prostate, there were no significant linear trends in stage at diagnosis versus age of the patient.

Age Factors↗

Clinical features of a population-based series of patients with lung cancer presenting with a solitary nodule.

We assessed survival in a population-based series of patients with lung cancer presenting with a solitary nodule. Using a population-based cancer registry, we identified 674 incident lung cancer cases in Bernalillo County, New Mexico, from 1977 to 1981. Both clinical information and chest roentgenograms were reviewed to identify 83 solitary nodule cases and 479 nonsolitary nodule cases. Chest roentgenograms were unavailable for 112. There were 83 patients with solitary nodules (55 men and 28 women), and adenocarcinoma was the predominant cell type. Overall, 5-yr survival was significantly greater for the patients with solitary nodules (24%) than for those with nonsolitary nodules (8%) (p less than 0.001). Of the 41 patients with solitary nodules who had surgery and Stage I disease, 49% lived 5 yr. In contrast, none of the 39 who did not have surgery lived longer than 2 yr. Our results imply that the varying survival described in previous series of patients with solitary nodules reflects different patient selection criteria.

Adult↗

Personal and family history of respiratory disease and lung cancer risk.

Lung cancer risk associated with family and personal history of respiratory diseases was assessed in a population-based, case-control study that included incident cases in New Mexico, 1980 to 1982. The study questionnaire ascertained previous diagnoses of major chronic respiratory diseases in the index subjects, their parents, and their grandparents and of lung and other respiratory cancers in the parents and grandparents. Physician diagnoses of chronic bronchitis, emphysema, asthma, and other chest illnesses were reported significantly more often for cases than for control subjects. For 6.9% of the cases, at least 1 parent had a diagnosis of lung cancer, whereas only 2.2% of the control subjects' parents were similarly affected (p less than 0.001). In multiple logistic regression models that excluded never smokers and included variables to control for the effects of cigarette smoking, we found significantly increased risks for a personal history of chronic bronchitis or emphysema (odds ratio = 2.0; 95% confidence interval, 1.4 to 2.8) and a parental history of lung cancer (odds ratio = 5.3; 95% confidence interval, 2.2 to 12.8). The present study complements the results of previous investigations, which demonstrated that lung cancer risk in smokers is modified by characteristics of the smoker and by family history.

Aged↗

Contribution of radon and radon daughters to respiratory cancer.

This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime.

Carcinoma, Bronchogenic↗

Childhood cancer epidemiology in New Mexico's American Indians, Hispanic whites, and non-Hispanic whites, 1970-82.

The statewide population-based New Mexico Tumor Registry identified 473 malignant tumors among children of ages 0-14 years, during the period 1970-82. There were 235 non-Hispanic whites (50%), 189 Hispanic whites (40%), 38 American Indians (8%), and 11 other nonwhites (2%). The average annual age-adjusted incidence rates per million for non-Hispanic whites were 138.6 for males and 108.3 for females; for Hispanic whites, the rates were 108.5 for males and 80.9 for females; for American Indians, the rates were 75.5 for males and 78.0 for females. The incidence rates for all sites of cancer combined were lower for Hispanics and American Indians than for New Mexico's non-Hispanic whites and U.S. whites. Leukemia was the most common cancer in all racial-ethnic groups. In comparison with U.S. whites, American Indians were at low risk for leukemias, lymphomas, central nervous system (CNS), sympathetic nervous system (SNS), and kidney tumors and were at high risk for retinoblastoma, bone, and sex organ tumors. Hispanics were at low risk for CNS, SNS, kidney, sex organ, and liver tumors. Hispanic and non-Hispanic white males both were at increased risk for melanoma.

Adolescent↗