Health-related quality of life in current smokers with COPD: factors associated with current smoking and new insights into sex differences

Abstract

Findings from studies that examined the association between health-related quality of life (HRQOL) and smoking status among COPD patients have been mixed. Moreover, factors associated with current smoking in COPD patients and differences by sex have not been fully elucidated. Data from the 2011 and 2012 Behavioral Risk Factor Surveillance System was used in this study. Four HRQOL indicators were examined in this study: general health, physical health, mental health, and activity limitations. General health was dichotomized into two groups: “excellent/very good/good” and “fair/poor”, and the other three HRQOL indicators were dichotomized into <14 (infrequent) and ≥14 (frequent) unhealthy days in the past 30 days. To examine HRQOL indicators in association with current versus former smoking and identify factors associated with current smoking, logistic regression models were used. Sex differences were explored. In COPD patients, current smokers compared to former smokers had significantly poor HRQOL on all subdomains: “fair/poor” general health (adjusted odds ratio [AOR]: 1.2 [95% confidence interval {CI}: 1.1–1.5]); poor physical health (AOR: 1.3 [CI: 1.1–1.5]); poor mental health (AOR: 1.8 [CI: 1.4–2.2]); and poor activity limitations (AOR: 1.5 [CI: 1.3–1.9]). HRQOL subdomains affected by current smoking differed by sex except activity limitations. General health (AOR: 1.5 [CI: 1.1–2.0]) and activity limitations (AOR: 1.6 [95% CI: 1.2–2.2]) in males and physical health (AOR: 1.3 [CI: 1.0–1.6]), mental health (AOR: 2.1 [CI: 1.7–2.6]), and activity limitations (AOR: 1.5 [CI: 1.2–1.9]) in females were significantly impaired due to current smoking. Factors associated with current smoking differed by sex except being unmarried and having less than a college degree, which were associated with current smoking in both males and females. These findings have important implications for health care providers in designing more effective interventions which tailor to and target specific subgroups for smoking cessation.