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 FEV(1)/FVC <0.7 which corresponds to COPD I and higher (COPD I+) according to current GOLD guidelines. Significant AO was defined as FEV(1)/FVC <0.7 and FEV(1) <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.

Farming and the prevalence of non-reversible airways obstruction: results from a population-based study.

INTRODUCTION: Occupational exposure to noxious dusts, gases, and fumes most likely contributes to obstructive lung disease. We studied whether self-reported farming work is associated with non-reversible airways obstruction. METHODS: Following the burden of obstructive lung disease (BOLD) study protocol, we surveyed a gender-stratified population-based sample of 2,200 adults aged 40 years and over. Pre- and post-bronchodilator spirometry, as well as information on smoking, occupation, and reported respiratory disease was recorded. According to GOLD criteria, non-reversible airways obstruction was defined as a post-bronchodilator forced expiratory volume (FEV(1))/forced vital capacity (FVC) < 0.70. Occupational and smoking history was based on questionnaire. Farming was defined as ever working in this occupation for 3 months or longer. RESULTS: For 1,258 participants with complete data (post-bronchodilator spirometry and questionnaire data), 288 (=22.9%) reported farming. Among the 288 participants reporting farming, the prevalence of non-reversible airways obstruction was 30.2%. Farming was significantly associated with airways obstruction: chronic obstructive pulmonary disease (COPD) GOLD stage I or higher (OR 1.5; 95% CI 1.1-2.0) and COPD GOLD stage II or higher (OR 1.8; 95% CI 1.2-2.7). The latter estimate was unchanged when adjustment for competing risks gender, age, and smoking was done. In this population the risk for non-reversible airways obstruction attributable to farming was 7.7%. CONCLUSION: Farming should be considered a risk factor for non-reversible airways obstruction.