title: The prevalence of chronic obstructive pulmonary disease in Riyadh, Saudi Arabia: a BOLD study.
abstract: OBJECTIVE
  To estimate the prevalence and associated risk factors of chronic obstructive pulmonary disease (COPD) in Saudi adults aged ⩾40 years using standardised post-bronchodilator spirometry according to the Burden of Obstructive Lung Disease (BOLD) protocol.
  
  
  METHODS
  Saudi men and women aged ⩾40 years were recruited by stratified multistage random sampling in Riyadh, Saudi Arabia. Participants completed questionnaires on respiratory symptoms and exposure to risk factors for COPD. Spirometry was performed according to standard methods. COPD was defined as post-bronchodilator FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratio <70% (Global Initiative for Obstructive Lung Disease [GOLD]) or less than the lower limit of normal (LLN) (95(th) percentile) of the population distribution for FEV1/FVC.
  
  
  RESULTS
  Seven hundred subjects underwent acceptable post-bronchodilator spirometry. The overall prevalence of GOLD COPD was 4.2% (men 5.7%, women 2.5%). The overall prevalence of COPD stage 1 or higher using the LLN was lower than estimates using the GOLD criteria (3.2%). The overall prevalence of GOLD stage 2 or higher COPD was 3.7%. Male sex, increasing age and smoking were significantly associated with COPD diagnosis.
  
  
  CONCLUSIONS
  The overall prevalence of COPD in Saudi Arabia is 4.2%. Male, increasing age and smoking were the main risk factors for COPD.
authors.affiliation: Department of Medicine, College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: M
authors.initials: M
authors.lastname: Al Ghobain
authors.affiliation: Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: E H
authors.initials: EH
authors.lastname: Alhamad
authors.affiliation: Respiratory Care, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: H S
authors.initials: HS
authors.lastname: Alorainy
authors.affiliation: Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: F
authors.initials: F
authors.lastname: Al Kassimi
authors.affiliation: Department of Pulmonary and Critical Care Medicine, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: H
authors.initials: H
authors.lastname: Lababidi
authors.affiliation: Department of Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: M S
authors.initials: MS
authors.lastname: Al-Hajjaj
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013147:Spirometry; D011795:Surveys and Questionnaires; D014797:Vital Capacity
chemical_list: D001993:Bronchodilator Agents