Supplementary Material for: The Effect of Hidden Female Smoking on the Association between Smoking and Asthma

Background: The association between smoking and asthma remains controversial. In our previous study, we were not able to show an association between asthma and smoking in Korean adults. One Korean study demonstrated underreporting of smoking history by female adults. The aim of the present study was to investigate the effects of hidden female smoking on the association between asthma and smoking in Korean adults. Methods: Data were acquired from 23,483 men and women aged ≥19 years who participated in the Korean National Health and Nutrition Examination Surveys (KNHANES). Results: The prevalence of asthma was 1.5%, the self-reported smoking prevalence was 32.4%, and the cotinine-verified smoking prevalence was 30.3%. Of the male cotinine-verified smokers, 6.4% were self-reported nonsmokers (2.7% never smokers and 3.7% ex–smokers), whereas 48.8% of the female cotinine-verified smokers were self-reported nonsmokers (43.2% never smokers and 5.6% ex–smokers). In males, the adjusted odds ratio of the association between smoking and asthma was 0.738 (confidence interval, CI: 0.393–1.173) in self-reported and 0.767 (CI: 0.515–1.143) in cotinine-verified smoking; in females, the adjusted odds ratio was 1.945 (CI: 1.348–2.805) in self-reported and 1.531 (CI: 1.076–2.179) in cotinine-verified smoking. Conclusions: Our study showed smoking was associated with asthma in females but not in males.背景：吸烟与哮喘的关联仍存争议。本团队既往研究未能证实韩国成人哮喘与吸烟存在相关性。此前一项韩国研究发现，女性成人存在吸烟史漏报情况。本研究旨在探讨隐匿性女性吸烟对韩国成人哮喘与吸烟之间关联的影响。方法：研究数据取自参与韩国全国健康与营养检查调查（Korean National Health and Nutrition Examination Surveys, KNHANES）的23483名年龄≥19岁的男女受试者。结果：本研究中哮喘患病率为1.5%，自我报告吸烟率为32.4%，经可替宁（cotinine）验证的吸烟率为30.3%。在经可替宁验证的男性吸烟者中，6.4%为自我报告的非吸烟者（其中2.7%为从未吸烟者，3.7%为既往吸烟者）；而在经可替宁验证的女性吸烟者中，48.8%为自我报告的非吸烟者（其中43.2%为从未吸烟者，5.6%为既往吸烟者）。男性群体中，自我报告吸烟场景下哮喘与吸烟关联的校正比值比为0.738（置信区间CI：0.393~1.173），经可替宁验证吸烟场景下该关联的校正比值比为0.767（CI：0.515~1.143）；女性群体中，自我报告吸烟场景下的校正比值比为1.945（CI：1.348~2.805），经可替宁验证吸烟场景下为1.531（CI：1.076~2.179）。结论：本研究证实，吸烟与女性哮喘存在关联，而与男性哮喘无显著相关性。