Chest
Volume 139, Issue 4, April 2011, Pages 752-763
Journal home page for Chest

Original Research
COPD
COPD in Never Smokers: Results From the Population-Based Burden of Obstructive Lung Disease Study

https://doi.org/10.1378/chest.10-1253Get rights and content
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Background

Never smokers comprise a substantial proportion of patients with COPD. Their characteristics and possible risk factors in this population are not yet well defined.

Methods

We analyzed data from 14 countries that participated in the international, population-based Burden of Obstructive Lung Disease (BOLD) study. Participants were aged ≥ 40 years and completed postbronchodilator spirometry testing plus questionnaires about respiratory symptoms, health status, and exposure to COPD risk factors. A diagnosis of COPD was based on the postbronchodilator FEV1/FVC ratio, according to current GOLD (Global Initiative for Obstructive Lung Disease) guidelines. In addition to this, the lower limit of normal (LLN) was evaluated as an alternative threshold for the FEV1/FVC ratio.

Results

Among 4,291 never smokers, 6.6% met criteria for mild (GOLD stage I) COPD, and 5.6% met criteria for moderate to very severe (GOLD stage II+) COPD. Although never smokers were less likely to have COPD and had less severe COPD than ever smokers, never smokers nonetheless comprised 23.3% (240/1,031) of those classified with GOLD stage II+ COPD. This proportion was similar, 20.5% (171/832), even when the LLN was used as a threshold for the FEV1/FVC ratio. Predictors of COPD in never smokers include age, education, occupational exposure, childhood respiratory diseases, and BMI alterations.

Conclusion

This multicenter international study confirms previous evidence that never smokers comprise a substantial proportion of individuals with COPD. Our data suggest that, in addition to increased age, a prior diagnosis of asthma and, among women, lower education levels are associated with an increased risk for COPD among never smokers.

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Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (http://www.chestpubs.org/site/misc/reprints.xhtml).

Funding/Support: The BOLD initiative was funded in part by unrestricted educational grants to the operations center from ALTANA, Aventis, AstraZeneca, Boehringer-Ingleheim, Chiesi, GlaxoSmithKline, Merck, Novartis, Pfizer Inc, Schering-Plough, Sunovion Pharmaceuticals Inc, and the University of Kentucky.

*

A complete list of the members of the BOLD Collaborative Research Group is available in e-Appendix 1.