1. Socioeconomic Status, Smoking, and Lung Cancer: Mediation and Bias Analysis in the SYNERGY Study.
- Author
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Hovanec J, Kendzia B, Olsson A, Schüz J, Kromhout H, Vermeulen R, Peters S, Gustavsson P, Migliore E, Radoi L, Barul C, Consonni D, Caporaso NE, Landi MT, Field JK, Karrasch S, Wichmann HE, Siemiatycki J, Parent ME, Richiardi L, Simonato L, Jöckel KH, Ahrens W, Pohlabeln H, Fernández-Tardón G, Zaridze D, McLaughlin JR, Demers PA, Świątkowska B, Lissowska J, Pándics T, Fabianova E, Mates D, Schejbalova M, Foretova L, Janout V, Boffetta P, Forastiere F, Straif K, Brüning T, and Behrens T
- Subjects
- Humans, Male, Female, Case-Control Studies, Middle Aged, Aged, Adult, Logistic Models, Risk Factors, Odds Ratio, Lung Neoplasms epidemiology, Smoking epidemiology, Social Class, Bias, Mediation Analysis
- Abstract
Background: Increased lung cancer risks for low socioeconomic status (SES) groups are only partially attributable to smoking habits. Little effort has been made to investigate the persistent risks related to low SES by quantification of potential biases., Methods: Based on 12 case-control studies, including 18 centers of the international SYNERGY project (16,550 cases, 20,147 controls), we estimated controlled direct effects (CDE) of SES on lung cancer via multiple logistic regression, adjusted for age, study center, and smoking habits and stratified by sex. We conducted mediation analysis by inverse odds ratio weighting to estimate natural direct effects and natural indirect effects via smoking habits. We considered misclassification of smoking status, selection bias, and unmeasured mediator-outcome confounding by genetic risk, both separately and by multiple quantitative bias analyses, using bootstrap to create 95% simulation intervals (SI)., Results: Mediation analysis of lung cancer risks for SES estimated mean proportions of 43% in men and 33% in women attributable to smoking. Bias analyses decreased the direct effects of SES on lung cancer, with selection bias showing the strongest reduction in lung cancer risk in the multiple bias analysis. Lung cancer risks remained increased for lower SES groups, with higher risks in men (fourth vs. first [highest] SES quartile: CDE, 1.50 [SI, 1.32, 1.69]) than women (CDE: 1.20 [SI: 1.01, 1.45]). Natural direct effects were similar to CDE, particularly in men., Conclusions: Bias adjustment lowered direct lung cancer risk estimates of lower SES groups. However, risks for low SES remained elevated, likely attributable to occupational hazards or other environmental exposures., Competing Interests: Disclosure: The authors do not declare any conflict of interest. J.H., B.K., T. Brüning, and T. Behrens, as staff of the Institute for Prevention and Occupational Medicine (IPA), are employed by the study’s main financing body, the German Social Accident Insurance. IPA is an independent research institute of the Ruhr-University Bochum. The authors are independent of the German Social Accident Insurance in study design, access to the collected data, responsibility for data analysis and interpretation, and the right to publish. The views expressed in this article are those of the authors and not necessarily those of the sponsor. Where authors are identified as personnel of the International Agency for Research on Cancer/World Health Organization, the authors alone are responsible for the views expressed in this article and they do not necessarily represent the decisions, policies, or views of the International Agency for Research on Cancer/World Health Organization., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2025
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