Table 1.
Definition of asthma, COPD and asthma COPD overlap syndrome per study.
| Author | N, age | Asthma | COPD | Overlap |
|---|---|---|---|---|
|
Miravitlles
et al. [2013]
EPI-SCAN |
N = 4274 40–80 years |
PB FEV1/FVC < 0.7 | PB FEV1/FVC < 0.7 and previous diagnosis of asthma | |
| Magnussen et al. [2008] |
N = 472 ⩾40 years |
Physician diagnosis asthma < 30 years, diagnosis COPD, PB FEV1/FVC < 0.7, PB FEV1 < 80% pred, > 10 PY, ICS previous year, documented BDR ⩾ 12%/200 ml | ||
| Siva et al. [2007] |
N = 82 >45 years |
History COPD, PB FEV1/FVC < 0.7, PB FEV1 < 80% pred, no BRD (FEV1 < 15% and < 200 ml), no history of asthma, no comorbidities | ||
| Fabbri et al. [2003] |
N = 46 >50 years |
PB < 0.7, history of asthma, documented previous variable airflow obstruction, < 5 PY | PB < 0.7, history of COPD, > 20 PY | |
| Fu et al. [2014] |
N = 108 >55 years |
Diagnosis obstructive airway disease, PB FEV1/FVC > 0.7, PB FEV1 > 80% pred, AHR or BDR | Diagnosis obstructive airway disease, PB FEV1/FVC < 0.7, PB FEV1 < 80% pred, no AHR or BDR | Diagnosis obstructive airway disease, PB FEV1/FVC < 0.7, PB FEV1 < 80% pred, with AHR or BDR |
|
Hardin
et al. [2011, 2014] COPDgene study |
N = 3570 45–80 years |
> 10 PY, PB FEV1/FVC < 0.7, PB FEV1 < 80% | >10 PY, PB FEV1/FVC < 0.7, PB FEV1 < 80%, previous diagnosis of asthma < 40 years | |
|
Menezes
et al. [2014]
PLATINO |
N = 5044 >40 years |
(Self-reported) diagnosis of asthma, symptoms of wheezing and BDR > 12% + 200 ml | PB FEV1/FVC < 0.7, PB FEV1/FEV6 < LLN, FEV1/FVC < LLN | Symptoms of wheezing and BDR > 12% + 200 ml, PB FEV1/FVC < 0.7 |
|
De Marco
et al. [2007]
GEIRD study |
N = 8360 20–85 years |
Self-reported physician diagnosis asthma | Self-reported physician diagnosis COPD | |
|
Iwamoto
et al. [2014]
FinnCADstudy |
N = 134 >40 years |
History of asthma, BDR > 12% in FEV1 or > 15% in PEF, > 20% diurnal variation PEF, BHR | PB FEV1/FVC < 0.7, long-term smoking | History of asthma, BDR > 12% in FEV1 or > 15% in PEF, >20% diurnal variation PEF, BHR, PB FEV1/FVC < 0.7, long-term smoking |
| Bumbacea et al. [2004] | N = 175 | Chronic symptoms of asthma, previous variation obstruction > 15%, PB FEV1 > 80% | Chronic symptoms of asthma, previous variation obstruction > 15%, persistent obstruction PB FEV1 < 50% | |
|
Chung
et al. [2014]
NHANES IV survey |
N = 9104 | Wheezing, FEV1/FVC ratio > 0.7 | No wheezing, FEV1/FVC ratio < 0.7 | Wheezing, FEV1/FVC ratio < 0.7 |
| Kauppi et al. [2011] |
N = 1546 18–75 years |
BDR FEV1 ⩾ 12%, BDR PEF ⩾ 15%/diurnal variation ⩾ 20%, BHR, decrease FEV1 ⩾ 15% in exercise test | Long-term smoking, BD FEV1/FVC < 0.70 | Combination of asthma and COPD |
| Contoli et al. [2010] |
N = 52 >50 years |
History of asthma, PB FEV1/FVC > 0.7, previous positive BDR, < 5 PY | History of COPD, PB FEV1/FVC < 0.7, > 20 PY, no previous positive BDR | History of asthma, PB FEV1/FVC < 0.7, previous positive BDR, < 5 PY |
|
| ||||
| Boulet et al. [2003] |
N = 38 24–70 years |
History of asthma, positive BDR ⩾ 15%, FEV1 > 80% pred (spontaneous or with ICS or oral steroids), < 10 PY | History of asthma, positive BDR ⩾ 15%, FEV1 < 75% pred despite ICS or oral steroids, < 10 PY | |
| Kitaguchi et al. [2012] |
N = 63 >60 years |
History of COPD, PB FEV1/FVC < 0.7, > 30 PY | History of COPD and asthma, PB FEV1/FVC < 0.7, > 30 PY | |
| Diaz-Guzman et al. [2011] |
N = 15,203 >25 years |
Self-reported asthma | Self-reported COPD | Self-reported asthma and COPD |
N = number
AHR, airway hyperresponsiveness; BDR, bronchodilator response; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; ICS, inhaled corticosteroid; LLN, lower limit of normal; pred, predicted; PY, pack years; PB, post bronchodilator.