Non-reversible airway obstruction in never smokers: Results from the Austrian BOLD study

Background: The presence of non-reversible airway obstruction (AO) in never smokers has only received limited attention until now. Methods: We analyzed data from the Austrian Burden of Obstructive Lung Disease (BOLD) study. We defined non-reversible AO as post-bronchodilator FEV₁/FVC <0.7 which corresponds to COPD I and higher (COPD I+) according to current GOLD guidelines. Significant AO was defined as FEV₁/FVC <0.7 and FEV₁ <80% predicted (GOLD II and higher, GOLD II+). The prevalence and characteristics of non-reversible AO in never smokers were analyzed in relation to the severity of the disease. Results: Never smokers comprised 47.3% of the study population. Non-reversible AO was seen in 18.2% of never smokers, and 5.5% of never smokers fulfilled criteria for significant non-reversible AO (GOLD stage II+). Therefore, the resulting population prevalence of significant non-reversible AO (GOLD stage II+) was 2.6%. Never smokers with non-reversible AO were predominantly female and slightly older. The airway obstruction was found to be less severe as compared with ever smokers. Despite this, 20% of never smokers with significant non-reversible AO (GOLD stage II+) reported respiratory symptoms and 50% reported impairment of quality of life. This burden of illness in never smokers was similar to that in smokers when severity of AO was taken into account. Conclusion: Approximately every third subject with non-reversible AO has never smoked, yet still demonstrates a substantial burden of symptoms and impairment of quality of life. Never smokers should receive far greater attention when efforts are undertaken to prevent and treat chronic airway obstruction.