Abstract
In China, the burden of chronic obstructive disease (COPD) is high in never-smokers but little is known about its causes in this group.
We analysed data on 287 000 female and 30 000 male never-smokers aged 30–79 years from 10 regions in China, who participated in the China Kadoorie Biobank baseline survey (2004–2008). Prevalence of airflow obstruction (AFO) (pre-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7 and below the lower limit of normal (LLN)) was estimated, by age and region. Cross-sectional associations of AFO (FEV1/FVC <0.7), adjusted for confounding, were examined.
AFO prevalence defined as FEV1/FVC <0.7 was 4.0% in females and 5.1% in males (mean ages 51 and 54 years, respectively). AFO prevalence defined as FEV1/FVC <LLN was 5.9% and 5.2%, respectively. In females, odds ratios of AFO were positively associated with lower household income (1.63, 95% CI 1.55–1.72 for lowest versus highest income groups), prior tuberculosis (2.36, 95% CI 2.06–2.71), less education (1.17, 95% CI 1.12–1.23 for no schooling versus college education), rural region and lower body mass index. AFO was positively associated with cooking with coal but not with other sources of household air pollution. Associations were similar for males.
AFO is prevalent in Chinese never-smokers, particularly among those with low socioeconomic status or prior tuberculosis, and in rural males.
Abstract
Airflow obstruction is prevalent in Chinese never-smokers and particularly associated with low socioeconomic status http://ow.ly/sG481
Footnotes
Chinese correspondence may be addressed to L. Li. E-mail: lmlee@vip.163.com
This article has supplementary material available from www.erj.ersjournals.com
For editorial comments see page 8.
Support statement: The baseline survey and first re-survey in China were supported by a research grant from the Kadoorie Charitable Foundation in Hong Kong; follow-up of the project during 2009–2014 is supported by the Wellcome Trust in the UK (grant 088158/Z/09/Z) and the National Key Technology Research and Development Program of the 12th Five-Year Plan, Ministry of Science and Technology, China; the CTSU at Oxford University also receives core funding for it from the UK Medical Research Council, the British Heart Foundation (BHF) and Cancer Research UK. Support for the present study was provided by GlaxoSmithKline (WEUKBRE5848). Z. Chen and R. Collins acknowledge support from the BHF Centre of Research Excellence, Oxford.
Conflict of interest: None declared.
- Received September 2, 2013.
- Accepted December 31, 2013.
- ©ERS 2014
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