Abstract: Objective To explore the prevalence of chronic obstructive pulmonary disease （COPD） among smokers aged ≥40 years in Qingdao City, and analyze the related factors of COPD. Methods From August to December 2021, the multi-stage stratified cluster random sampling method was used to select smokers aged ≥ 40 years in households with smoking habits as the survey subjects to carry out the questionnaire, physical examination, and pulmonary function test. The prevalence of COPD among smokers was analyzed, and the influencing factors of COPD were studied. Results A total of 1 516 smokers were enrolled, 81.06% of whom were male, 70.25% of whom had ≥ 21 pack-years of cigarette smoking, and 71.17% of whom had smoked for more than 30 years. COPD occurred in 297 cases （19.59%）. Multivariate Logistic analysis showed that males （OR=3.706）, aged 50-59 years （OR=1.567）, aged 60-69 years （OR=2.585）, aged ≥70 years （OR=4.926）, urban residents （OR=1.568）, body mass index （BMI） <18.5 kg/m² （OR=3.848）, passive smoking （OR=2.516）, 11-20 pack-years of cigarette smoking （OR=1.903）, 21-30 pack-years of cigarette smoking （OR=2.472）, ≥31 pack-years of cigarette smoking （OR=3.792）, smoked for 31-40 years （OR=2.400）, and smoked for ≥ 40 years （OR=4.227） were risk factors for COPD in smokers. Tendency χ² analysis showed that the incidence of COPD in smokers increased with the increase of pack-years of cigarette smoking and smoking years （both P<0.01）. Spearman correlation analysis showed that the severity of COPD was significantly and positively correlated with pack-years of cigarette smoking and smoking years. The severity of COPD would continue to deepen with the increase of pack-years of cigarette smoking and smoking years （both P<0.01）. Conclusion The smokers aged ≥40 years in Qingdao are mainly male, and the incidence of COPD is high. Male, old age, urban residents, low BMI, and passive smoking were risk factors for COPD. The higher the number of pack-years of cigarette smoking and smoking years, the higher the risk of COPD.

Key words: Smokers, Chronic obstructive pulmonary disease, Respiratory disease, Influencing factor