10.6084/m9.figshare.5129176.v1 Andreeva E. Andreeva E. Pokhaznikova M. Pokhaznikova M. Lebedev A. Lebedev A. Moiseeva I. Moiseeva I. Kutznetsova O. Kutznetsova O. Degryse J.-M. Degryse J.-M. Supplementary Material for: The Prevalence of Chronic Obstructive Pulmonary Disease by the Global Lung Initiative Equations in North-Western Russia Karger Publishers 2016 Chronic obstructive pulmonary disease Tobacco Spirometry reference values Epidemiology of chronic obstructive pulmonary disease and asthma 2016-01-05 00:00:00 Dataset https://karger.figshare.com/articles/dataset/Supplementary_Material_for_The_Prevalence_of_Chronic_Obstructive_Pulmonary_Disease_by_the_Global_Lung_Initiative_Equations_in_North-Western_Russia/5129176 <b><i>Background:</i></b> The prevalence of chronic obstructive pulmonary disease (COPD) varies in different countries, while the cut-off for airflow obstruction (AO) is still contested. No COPD prevalence data based on the Global Lung Initiative (GLI) 2012 equations are available in Russia. <b><i>Objectives:</i></b> This study aims to assess AO prevalence by the GLI lower limit of normal (GLI-LLN) and the fixed cut-off, to identify AO risk factors and to assess the diagnostic value of respiratory symptoms in north-western Russia. <b><i>Methods:</i></b> In a north-western Russian population-based sample of 2,974 adults aged 35-70 years, data on socio-demographics, smoking, occupational exposures and respiratory symptoms were collected, and spirometry was performed before and after bronchodilator (BD) administration. <b><i>Results:</i></b> The AO prevalence was 6.8% (95% CI 5.8-7.9) based on the fixed and 4.8% (95% CI 3.9-5.7) based on the GLI-LLN cut-off. 22.5% of the participants with post-BD AO had a positive bronchodilator test, and 1% showed a paradoxical BD response. Of the environmental factors studied, only smoking was independently associated with AO (odds ratio 2.47, 95% CI 1.60-3.82). The positive predictive value of respiratory symptoms for AO was 11% based on the fixed and 8% based on the GLI-LLN cut-off. <b><i>Conclusions:</i></b> In a sample of adults in north-western Russia, the AO prevalence by the GLI-LLN cut-off was lower than that by the fixed cut-off. The predictive value of respiratory symptoms was low.