title: Determinants of underdiagnosis of COPD in national and international surveys.
abstract: BACKGROUND
  COPD ranks within the top three causes of mortality in the global burden of disease, yet it remains largely underdiagnosed. We assessed the underdiagnosis of COPD and its determinants in national and international surveys of general populations.
  
  
  METHODS
  We analyzed representative samples of adults aged ≥ 40 years randomly selected from well-defined administrative areas worldwide (44 sites from 27 countries). Postbronchodilator FEV1/FVC < lower limit of normal (LLN) was used to define chronic airflow limitation consistent with COPD. Undiagnosed COPD was considered when participants had postbronchodilator FEV1/FVC < LLN but were not given a diagnosis of COPD.
  
  
  RESULTS
  Among 30,874 participants with a mean age of 56 years, 55.8% were women, and 22.9% were current smokers. Population prevalence of (spirometrically defined) COPD ranged from 3.6% in Barranquilla, Colombia, to 19.0% in Cape Town, South Africa. Only 26.4% reported a previous lung function test, and only 5.0% reported a previous diagnosis of COPD, whereas 9.7% had a postbronchodilator FEV1/FVC < LLN. Overall, 81.4% of (spirometrically defined) COPD cases were undiagnosed, with the highest rate in Ile-Ife, Nigeria (98.3%) and the lowest rate in Lexington, Kentucky (50.0%). In multivariate analysis, a greater probability of underdiagnosis of COPD was associated with male sex, younger age, never and current smoking, lower education, no previous spirometry, and less severe airflow limitation.
  
  
  CONCLUSIONS
  Even with substantial heterogeneity in COPD prevalence, COPD underdiagnosis is universally high. Because effective management strategies are available for COPD, spirometry can help in the diagnosis of COPD at a stage when treatment will lead to better outcomes and improved quality of life.
authors.affiliation: Department of Pulmonary Medicine, Kepler University Hospital, Linz, Austria; Faculty of Medicine, Johannes-Kepler-University, Linz, Austria. Electronic address: bernd.lamprecht@akh.linz.at.
authors.forename: Bernd
authors.initials: B
authors.lastname: Lamprecht
authors.affiliation: Instituto de Investigación, Hospital Universitario de la Princesa (IISP), Universidad Autónoma de Madrid, Catédra UAM-Linde, Madrid, Spain.
authors.forename: Joan B
authors.initials: JB
authors.lastname: Soriano
authors.affiliation: Department of Pulmonary Medicine, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Studnicka
authors.affiliation: Faculty of Medicine, Johannes-Kepler-University, Linz, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kaiser
authors.affiliation: Department of Respiratory Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands; Program Development Centre, CIRO+, Centre of Expertise for Chronic Organ Failure, Horn, The Netherlands.
authors.forename: Lowie E
authors.initials: LE
authors.lastname: Vanfleteren
authors.affiliation: Respiratory Epidemiology and Public Health, Imperial College, London, England.
authors.forename: Louisa
authors.initials: L
authors.lastname: Gnatiuc
authors.affiliation: Respiratory Epidemiology and Public Health, Imperial College, London, England.
authors.forename: Peter
authors.initials: P
authors.lastname: Burney
authors.affiliation: Servicio de Neumología, Hospital Universitari Vall d'Hebron, Ciber de Enfermedades Respiratorias (CIBERES), Barcelona, Spain.
authors.forename: Marc
authors.initials: M
authors.lastname: Miravitlles
authors.affiliation: Servicio de Neumología, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: García-Rio
authors.affiliation: Department of Radiology, General Hospital Linz (Akh Linz), Linz, Austria.
authors.forename: Kaveh
authors.initials: K
authors.lastname: Akbari
authors.affiliation: Servicio de Neumología, Hospital La Princesa, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Ancochea
authors.affiliation: Programa de Pós-Graduacão em Epidemiologia, Universidade Federal de Pelotas, Pelotas, Brazil.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Menezes
authors.affiliation: Institute of Respiratory Diseases, Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Perez-Padilla
authors.affiliation: Servicio de Neumonología, Hospital Universitario de Caracas, Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Maria
authors.initials: M
authors.lastname: Montes de Oca
authors.affiliation: Departamento de Investigación, Fundación Neumológica Colombiana, Bogotá, Colombia; Asociación Colombiana de Neumología y Cirugía de Tórax, Bogotá, Colombia.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Torres-Duque
authors.affiliation: Asociación Colombiana de Neumología y Cirugía de Tórax, Bogotá, Colombia; Clínica Reina Sofía, Bogotá, Colombia.
authors.forename: Andres
authors.initials: A
authors.lastname: Caballero
authors.affiliation: Departamento de Investigación, Fundación Neumológica Colombiana, Bogotá, Colombia.
authors.forename: Mauricio
authors.initials: M
authors.lastname: González-García
authors.affiliation: Oregon Health & Science University, Portland, OR.
authors.forename: Sonia
authors.initials: S
authors.lastname: Buist
mesh_terms: D000328:Adult; D000368:Aged; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005260:Female; D005541:Forced Expiratory Volume; D014943:Global Health; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology*; D011788:Quality of Life; D012307:Risk Factors; D012720:Severity of Illness Index; D013147:Spirometry; D014797:Vital Capacity