Different Characteristics of Ex-Smokers and Current Smokers with COPD: A Cross-Sectional Study in China

Chronic obstructive pulmonary disease (COPD), usually caused by tobacco smoking, is increased in China. Smoking cessation is the first step in COPD management. Data on predictors of smoking cessation are sparse in COPD patients in China. We aim to find the differences in the clinical characteristics between ex-smokers and current smokers with COPD to determine the factors related to smoking cessation.

From outpatient departments of 12 hospitals in Hunan and Guangxi provinces, a total of 4331 patients were included. Information on demographic and sociological data, lung function, and modified Medical Research Council (mMRC) dyspnea scale scores were recorded. Patients were divided into an ex-smokers group and a current smokers group based on whether they gave up smoking. A logistic regression analysis was performed to analyze the factors associated with smoking cessation.

Of the total, the mean age was 62.9±8.5 years, and 47.3% were ex-smokers. Compared with the current smokers, the ex-smokers were older, and had heavier dyspnea, more severe airflow limitation, fewer pack-years, shorter smoking duration, and a higher proportion of Global Initiative for Chronic Obstructive Lung Disease (GOLD) groups C and D. The logistic regression model showed that smoking cessation was negatively correlated with widowhood, years of smoking, and forced expiratory volume in 1 second (FEV1), but was positively correlated with age, education level, amount smoked, mMRC score, GOLD grades, and GOLD groups.

Among patients with COPD, more than half still smoked. In the group of patients who quit smoking, many of them quit rather late in age after they had significant symptoms. Several predictors of smoking cessation were identified, indicating that ex-smokers differ substantially from continuing smokers. This should be taken into account in smoking-cessation interventions.