ABSTRACT
Objective To investigate the effects of smoking on chronic obstructive pulmonary disease(COPD) and respiratory symptoms. Methods A multi-stage, stratified cluster sampling strategy was used to select participants aged 40 or older in 5 surveillance points of Anhui Province. Questionnaires, body measurements and spirometry were used to collect data. Based on complex sampling design, Logistic regression model was conducted to analyze the effects of smoking on COPD and respiratory symptoms. Results The smokers who had smoked for ≥30 pack-years accounted for 13.9% (95% CI:10.3%-17.5%, P＜0.001) of the total population. And the smokers who had smoked for ≥40 years accounted for 8.5% (95% CI:6.7%-10.3%, P＜0.001) of the total population. On average, one smoker had smoked for 32.4 years (95% CI:31.2-33.5). Average daily cigarette consumption of daily smokers was 21.1 cigarettes (95% CI:19.6-22.7). As shown by multiple-variables Logistic regression analyses, the risk of COPD and respiratory symptoms increased with the increment of smoking pack-years and duration (all Ptrend <0.001). Conclusions Smoking was associated with COPD and respiratory symptoms. The risk of developing COPD and respiratory symptoms was greater with the increment of smoking pack-years and duration.