Biomedical subjects

M Dosemeci

Publications and source records attributed to M Dosemeci.

132 records · Page 8Linked to original sources

PubMed1990

Does nondifferential misclassification of exposure always bias a true effect toward the null value?

The authors present some examples to demonstrate that in certain nondifferential misclassification conditions with polychotomous exposure variables, estimates of odds ratios for categories at intermediate level of risk can be biased away from the null or can change direction. In addition, the authors present two examples to demonstrate that the slope of the dose-response trend for the true distributions can change direction, creating a false inverse trend, even if the misclassification is nondifferential.

Bias↗

PubMed1989

Lung cancer risk, occupational exposure, and the debrisoquine metabolic phenotype.

The risk of lung cancer in smokers was examined based on the debrisoquine metabolic phenotype and on exposure to occupational lung carcinogens, specifically asbestos and polycyclic aromatic hydrocarbons. Extensive metabolizers of debrisoquine are at a 4-fold increased risk for lung cancer compared to poor metabolizers, after adjustment for age, sex, and smoking (pack-years), when only occupationally unexposed subjects are considered. Increased risk related to the debrisoquine metabolic phenotype was greatest for squamous and small cell histologies, and least for the adenocarcinoma subtype. Men with a history of exposure to occupational carcinogens had significantly increased risk of lung cancer (relative risk = 2.8), after adjustment for age and smoking. Considering the combined effect of the high risk extensive metabolizers debrisoquine metabolic phenotype and likely occupational exposure to asbestos, the relative excess risk for lung cancer was 18-fold. This finding is consistent with a synergism in risk between the ability to extensively metabolize debrisoquine and occupational exposure to lung carcinogens in male smokers. Debrisoquine phenotyping has potential for identifying carcinogen-exposed workers at high risk of lung cancer.

Asbestos↗

PubMedDate not supplied

Occupation and the risk of lung cancer by histologic types and morphologic distribution: a case control study in Turkey.

BACKGROUND: The lung cancer incidence rate in Turkey has been increasing since the early 1980's. Etiology of lung cancer could be affected by differences in lifestyle, working conditions, and occupational exposures. OBJECTIVES: A hospital based case-control study was conducted in Turkey to provide information on the role that occupation plays in lung cancer etiology and the relationship between occupations and histologic types and the morphologic distribution of lung cancer. METHODS: A total of 1,354 male cases and 1,519 controls were analysed. Basic information was obtained from patients from a standardised questionnaire. Occupational titles of the subjects were classified by standard occupational and industrial codes. Age- and smoking-adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Excess lung cancer occurred among fire-fighters (OR: 6.8, CI: 1.3-37.4), drivers (OR: 1.4, CI: 1.1-2.0), textile workers (OR: 1.7, CI: 1.1-2.7), water treatment plant workers (OR: 2.2, CI: 1.1-4.3) and highway construction workers (OR: 1.5, CI: 1.0-2.5). Workers in the textile and grain milling industries were shown to have a significant excess risk of squamous cell carcinoma. Textile workers, and those working at water treatment plants had excess risk of small cell carcinoma. Construction workers had excess risk of adenocarcinoma. Fire-fighters and workers at textile plants, grain mills, water treatment plants, and in steel production were exposed to a high risk of peripheral tumors while the risk of central tumors was excessive among drivers and highway construction workers. CONCLUSIONS: The risk of lung cancer was associated with several occupations and peripheral located tumors and squamous lung cancer was the most common type.

Adenocarcinoma↗

PubMedDate not supplied

Occupation and lung cancer risk in Leningrad Province, Russia.

To investigate the association between occupation and lung cancer risk in Leningrad Province, Russia, we identified 540 pathologically diagnosed lung cancer cases (474 males and 66 females) and 582 controls (453 males and 129 females) from the 1993-1998 autopsy records of the 88 state hospitals of the Province. Lifetime occupational histories were obtained from personal records coded according to the standard Russian occupational classification system. Lung cancer risk was increased in workers in the manufacturing industry, particularly in the food industry and wholesale/retail trade and in the miscellaneous manufacturing industry. An increased risk was also found in subjects employed in chemical and metal production for 10 years or more. When we considered the association between specific occupations and lung cancer, waste incineration operators and loaders exhibited an excess risk that increased with employment duration. The present study, which is the first to evaluate the risk of lung cancer by occupation in Russia, suggests the presence in Leningrad Province of exposure in the workplace to lung carcinogens that require further characterization to develop targeted and effective preventive measures.

Administrative Personnel↗

PubMedDate not supplied

[A retrospective evaluation of exposure to dichloromethane by using a job-exposure matrix].

The impact of three features of a job-exposure matrix has been tested in a case-control study that evaluated the association of occupational exposure to dichloromethane and astrocytic brain cancer. These features were probability of exposure, an exposure assessment by decades, and the use of a more specific coding system of industries and occupations. The introduction of each feature had a striking effect on the estimate of relative risk. The odds ratio increased from 1.47 with none of these features, to 2.47 with high probability of exposure, to 4.15 with high probability of exposure and the specific coding system, to 6.08 with all features combined. These results indicate that job-exposure matrices efficacy in reducing the degree of exposure misclassification may be greatly improved by the introduction of these features.

Astrocytoma↗

PubMedDate not supplied

An alternative test for trend in exposure-response analysis.

The Mantel-extension chi-square test for overall trend is commonly used in evaluating dose-response relationships in epidemiologic studies. As illustrated by others, it is not an optimal test for a monotonic dose-response. In addition, the result of this test depends heavily upon the scores assigned to the exposure categories. The selection of the score may have a substantial impact on the test statistic and consequently, on the interpretation of the study results. A monotonic dose-response relationship exists when risk increases (or decreases) with increasing exposure. Although the Mantel-extension test is one of the most cited test for trend, it is not a sensitive test to reflect the incremental risk change of a dose-response relationship which may potentially generate misleading results. We propose an alternative test for the evaluation of monotonic dose-response, which reconfigurates the Mantel-Haenszel chi square test for dichotomous exposure series into a polychotomous exposure series. The proposed test generates chi values that are sensitive to incremental increase (or decrease) in risk at each exposure category and does not require exposure scores. The test is a simple summation of Mantel-Haenszel chi statistics obtained in for 2 x 2 tables over adjacent exposure categories (i.e., the sum of Mantel-Haenszel chi values between categories 1 and 2, 2 and 3, 3 and 4 and 1-1 and 1). Several examples are presented to illustrate that the proposed test generates more realistic chi values than those obtained by the Mantel-extension test for trend.

Chi-Square Distribution↗