title: Validity of Questionnaire-Based Diagnosis of Chronic Obstructive Pulmonary Disease in Azar-Cohort Population.
abstract: BACKGROUND
  The clinical diagnosis of chronic obstructive pulmonary disease (COPD) should be considered in any patient who has dyspnea, chronic cough or sputum production, and diagnosis should be confirmed by performing spirometry in presence of airflow limitation. The aim of this study was to assess the validity of a questionnaire used to detect COPD based on spirometry findings.
  
  
  METHODS
  The validity of a questionnaire for COPD diagnosis was examined using spirometry based on both Global Initiative for Chronic Obstructive Lung Disease (GOLD) and American Thoracic Society/European Respiratory Society (ATS/ERS) criteria for patients 35 years old and older. In total, 350 questionnaires were completed. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio and negative likelihood ratio were calculated to determine the accuracy of the questionnaire.
  
  
  RESULTS
  The sensitivity of the questionnaire in detection of airflow limitation was 8.3% and 6.7% by the GOLD and the ATS/ERS criteria, respectively; whereas, specificity was 96% by both criteria.
  
  
  CONCLUSIONS
  The high specificity of the questionnaire indicates that the questionnaire is more capable to identify people who do not have airflow limitation; whereas, the low sensitivity of the questionnaire could underestimate the actual prevalence of COPD in the general population.
authors.affiliation: Department of Community Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Delara
authors.initials: D
authors.lastname: Laghusi
authors.affiliation: Social Determinants of Health Research Center, Tabriz, Iran.
authors.forename: Mahasti
authors.initials: M
authors.lastname: Alizadeh
authors.affiliation: Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Khalil
authors.initials: K
authors.lastname: Ansarin
authors.affiliation: Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Asgari
authors.affiliation: Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Nayyereh
authors.initials: N
authors.lastname: Amini Sani
keywords: COPD; GOLD criteria; Spirometry; Validity