title: Prevalence and correlates of airflow obstruction in ∼317,000 never-smokers in China.
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.
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK Margaret.smith@ctsu.ox.ac.uk.
authors.forename: Margaret
authors.initials: M
authors.lastname: Smith
authors.affiliation: Chinese Academy of Medical Sciences, Beijing School of Public Health, Peking University Health Sciences Center, Beijing.
authors.forename: Liming
authors.initials: L
authors.lastname: Li
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK.
authors.forename: Mareli
authors.initials: M
authors.lastname: Augustyn
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK.
authors.forename: Om
authors.initials: O
authors.lastname: Kurmi
authors.affiliation: China National Center for Food Safety Risk Assessment, Beijing.
authors.forename: Junshi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK.
authors.forename: Rory
authors.initials: R
authors.lastname: Collins
authors.affiliation: Chinese Academy of Medical Sciences, Beijing.
authors.forename: Yu
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Tongxiang Center for Disease Control, Tongxiang.
authors.forename: Yabin
authors.initials: Y
authors.lastname: Han
authors.affiliation: Liuzhou Center for Disease Control, Liuzhou.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Qin
authors.affiliation: Suzhou Center for Disease Control, Suzhou.
authors.forename: Guanqun
authors.initials: G
authors.lastname: Xu
authors.affiliation: Pengzhou Center for Disease Control, Pengzhou.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Chinese Academy of Medical Sciences, Beijing.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Bian
authors.affiliation: Henan Center for Disease Control, Zhengzhou, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Peto
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, UK.
authors.forename: Zhengming
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D016902:Air Pollution, Indoor; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology*; D015992:Body Mass Index; D002681:China; D003296:Cooking; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D012119:Respiration; D012907:Smoking; D013147:Spirometry; D011795:Surveys and Questionnaires; D014797:Vital Capacity