BACKGROUND: The beneficial effects of smoking cessation on the progression of COPD are well established. Nevertheless, many patients with COPD continue to smoke.

METHODS: In this nationwide hospital-based prospective follow-up study, we examined rates of smoking cessation and clinical and sociodemographic determinants of smoking cessation in 3,233 patients with COPD who smoked on outpatient contact during 2008 to 2012. Using multivariate Cox regression, we calculated hazard ratios (HRs) of quitting.

RESULTS: Within 1 and 5 years from first outpatient contact, the probability of quitting was 19% and 45%, respectively. In adjusted analyses, patients were less likely to quit if they were younger, with an HR of 0.84 (95% CI, 0.71-0.99) for patients aged 50 to 69 years and 0.53 (95% CI, 0.37-0.76) for patients aged 30 to 49, compared with those aged 70 years or older, who had lower income (HR, 0.79; 95% CI, 0.67-0.94), lived alone (HR, 0.75; 95% CI, 0.64-0.88), were unemployed (HR, 0.70; 95% CI, 0.54-0.90), had milder COPD with an HR of 0.67 (95% CI, 0.53-0.84) for Global Initiative for Chronic Obstructive Lung Disease (GOLD) A and 0.61 (95% CI, 0.47-0.80) for GOLD B compared with GOLD D, had Medical Research Council (MRC) dyspnea scale score < 4 (HR 0.80, 95% CI 0.68-0.95), or no history of exacerbations treated on an outpatient basis. (HR, 0.80; 95% CI, 0.68-0.93).

CONCLUSIONS: These findings reinforce that young and socioeconomically disadvantaged patients have more difficulties achieving timely smoking cessation. A novel finding is that patients with milder COPD are less likely to quit. The findings suggest a need for interventional studies focusing on these subgroups to ensure abstinence to halt disease progression.