National Epidemiological Case–Control Study of Pharmacological Smoking Cessation Treatment in Danish Patients with Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease (COPD) is a progressive lung disease that is mainly caused by smoking, and most patients with COPD are either former or current smokers. The optimal way to slow down disease progression and reduce overall mortality is for patients to stop smoking. Patients with COPD are known to have lower socio- economic status and to be more nicotine-dependent than most other smokers and therefore face difficulties when attempting to quit smoking. Pharmacological smoking cessation treatment is known to be the most effective. However, the extent to which this treatment is actually offered to Danish smokers with COPD is unknown. Aim: The aim of this study was to investigate if patients with COPD were more likely to redeem a prescription for smoking cessation medication compared with matched controls. Materials and Methods: The study was designed as a registry-based, non- interventional case-control study. All Danish patients with COPD (ICD-10-code J 44 chronic obstructive pulmonary disease) diagnosed between 2009 and 2015 were included (130,797 cases). Controls (252,216) were matched on age, gender and geography. Primary outcome was the number of redeemed prescriptions for smoking cessation medication. Results: We found that 12% of patients with COPD redeemed a prescription for smoking cessation medication during the eight-year study period. The odds ratio (OR) for redeeming a prescription on smoking cessation medicine was OR 6.22 for patients with COPD compared with their matched controls. We also found that patients with COPD were more likely to redeem smoking cessation medication if they were younger, female or single. Conclusion: There is substantial room for improvement with respect to pharmacological smoking cessation treatment in Danish patients with COPD. In-depth knowledge of factors contributing to the patients choice of smoking cessation treatment might allow for more personalized guidance of patients with COPD. Keywords: nicotine, bupropion, varenicline, smoking cessation, COPD