Titre :
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Is residual confounding a reasonable explanation for the apparent protective effects of beta-carotene found in epidemiologic studies of lung cancer in smokers ? (2002)
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Auteurs :
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Daniel-O STRAM ;
Mark HUBERMAN ;
Anna-H. Wu
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Type de document :
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Article
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Dans :
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American journal of epidemiology (vol. 155, n° 7, 2002)
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Pagination :
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622-628
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Langues:
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Anglais
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Mots-clés :
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Cancer
;
Tabagisme
;
Supplémentation
;
Thérapeutique
;
Prévention santé
;
Biais
;
Evaluation
;
Exposition
;
Epidémiologie
;
Homme
;
Appareil respiratoire [pathologie]
;
Bêta
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Résumé :
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[BDSP. Notice produite par INIST-CNRS ZUR0x9F0. Diffusion soumise à autorisation]. The results of three randomized trials of beta-carotene supplementation for the prevention of lung cancer among smokers are in contradiction to a large body of epidemiologic evidence for the reduction of risk of lung cancer among smokers with higher intake and/or higher serum levels of beta-carotene. Complicating this issue are widely noted negative associations between tobacco use and intake or serum levels of beta-carotene. Although observational studies attempt to control for reported smoking histories, the accuracy of self-reported smoking is uncertain ; correlations as low as 0.5 between reported and true smoking exposure are not inconsistent with studies of biomarkers of cigarette exposure. The authors developed a simple statistical model for random errors in reported smoking (relative to true tobacco exposure) and assumed a modest (inverse) relation between true tobacco exposure and serum beta-carotene. Calculations from this model, combined with a model for lung cancer contemplated by Doll and Peto (J Epidemiol Community Health 1978 ; 78 : 303-13), suggest that biases in assessment of smoking exposure between smokers with low versus high beta-carotene intake may plausibly explain much or all of the observed protective effect of high beta-carotene levels. Appropriate cohort studies of lung cancer in smokers, utilizing biomarkers of smoking, are needed and are presently ongoing.
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