Table 1 Characteristics of selected studies
Country | Study type | Population | Definition of COPD | Definition of undiagnosed COPD | Participants with COPD | Percentage undiagnosed | Quality rating | |
|---|---|---|---|---|---|---|---|---|
Ancochea et al. (2013) [21] | Spain | Cross-sectional (EPI-SCANa) | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of COPD (self-reported) | 386 | 73% | Good |
Balcells et al. (2015) [3] | Spain | Prospective cohort study | Hospitalized patients, all eligible patients were invited | Post-bronchodilator FEV1/FVC < 0.7, 3 months after discharge | Spirometric obstruction and no diagnosis of respiratory disease or regular use of pharmacological respiratory treatment (self-reported) | 342 | 34% | Good |
Herrera et al. (2016) [25] | Argentina, Colombia, Venezuela, Uruguay | Cross-sectional | Primary care clinics, convenience sample | Post-bronchodilator FEV1/FVC < 0.7 and LLN | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 309 | 77% | Fair |
Hill et al. (2010) [29] | Canada | Cross-sectional | Primary care clinics, convenience sample | Post-bronchodilator FEV1/FVC < 0.7 and FEV1 < 80% predicted | Spirometric obstruction and no previous diagnosis of COPD based on medical chart review over the previous 12-months | 107 | 46% | Good |
Hvidsten et al. (2010) [24] | Norway | Cross-sectional | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spriometric obstruction and being treated by a physician or admitted to hospital for a diagnosis of obstructive lung disease (asthma, chronic bronchitis, emphysema, or COPD) in the previous 12-months (self-reported) | 303 | 66% | Good |
Labonté et al. (2016) [30] | Canada | Prospective cohort study | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 505 | 70% | Fair |
Lamprecht et al. (2015) [4] | Global | Cross-sectional (BOLDb, PLATINOc, EPI-SCAN, PREPOCOLd) | General Population, random sample | Post-bronchodilator FEV1/FVC < LLN | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 2992 | 81% | Good |
Llordes et al. (2015) [31] | Spain | Cross-sectional | Primary care clinic, all eligible patients were invited | Post-bronchodilator FEV1/FVC < 0.7 in 2 tests 4 weeks apart (the 2nd after 4 weeks of pharmacological treatment) | Spirometric obstruction and no previous diagnosis of COPD in medical reports | 422 | 57% | Fair |
Mahishale et al. (2015) [32] | NR | Cross-sectional | Hospitalized patients, convenience sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of COPD (self-reported) | 404 | 56% | Poor |
Miravitlles et al. (2009) [22] | Spain | Cross-sectional (EPI-SCAN) | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 408 | 73% | Good |
Moreira et al. (2013) [16] | Brazil | Cross-sectional (PLATINO) | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 53 | 62% | Fair |
Nascimento et al. (2007) [17] | Brazil | Cross-sectional (PLATINO) | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 144 | 88% | Fair |
Queiroz et al. (2012) [27] | Brazil | Cross-sectional | Primary care clinics, convenience sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 63 | 71% | Good |
Schirnhofer et al. (2011) [23] | Austria | Cross-sectional (BOLD) | General Population, random sample | Post-bronchodilator FEV1/FVC < LLN | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 199 | 86% | Good |
Talamo et al. (2007) [18] | Brazil, Chile, Mexico, Uruguay, Venezuela | Cross-sectional (PLATINO | General Population, random sample | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and no previous diagnosis of chronic bronchitis, emphysema, or COPD (self-reported) | 758 | 89% | Good |
Zhang et al. (2013) [33] | China | Cross-sectional | Hospitalized patients, all eligible patients were invited | Post-bronchodilator FEV1/FVC < 0.7 | Spirometric obstruction and COPD not recorded as a discharge diagnosis in medical records | 705 | 93% | Fair |