title: The Prevalence of Chronic Obstructive Pulmonary Disease by the Global Lung Initiative Equations in North-Western Russia.
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Health and Society, Universitx00E9; Catholique de Louvain, Brussels, Belgium.
authors.forename: Elena
authors.initials: E
authors.lastname: Andreeva
authors.forename: Marina
authors.initials: M
authors.lastname: Pokhaznikova
authors.forename: Anatoly
authors.initials: A
authors.lastname: Lebedev
authors.forename: Irina
authors.initials: I
authors.lastname: Moiseeva
authors.forename: Olga
authors.initials: O
authors.lastname: Kutznetsova
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Degryse
mesh_terms: D000328:Adult; D000368:Aged; D001993:Bronchodilator Agents; D003371:Cough / Q000453:epidemiology*; D004417:Dyspnea / Q000453:epidemiology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D012016:Reference Values; D012426:Russia / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D013147:Spirometry; D014797:Vital Capacity
chemical_list: D001993:Bronchodilator Agents