Subjects | Total identified clusters | Overlap cluster | Overlap cluster characteristics | First author [ref.] |
27 asthma and 22 COPD patients | 4 | 5 (10.2) |
| Wardlaw [18] |
175 participants: Wellington Respiratory Survey | 5 | 15 (8.6) |
| Weatherall [19] |
191 patients ≥60 years of age (predominantly male smokers) with obstructive airway diseases | 3 | 59 (30.9) |
| Jo [20] |
389 subjects with symptoms of wheeze and breathlessness in last 12 months | 5 | 34 (8.7) |
| Fingleton [21] |
86 patients with severe asthma and 75 patients with moderate-to-severe COPD | 3 | 47 (27.4) |
| Ghebre [22] |
191 patients with doctor-diagnosed asthma or COPD | 4 | 58 (30.4) |
| Rootmensen [23] |
152 patients with asthma and 50 patients with COPD | 4 | 50 (24.8) |
| Hirai [24] |
877 patients with asthma and 228 patients with COPD: French national Bronchial Obstruction and Asthma Cohort | 3 | 386 (34.9) |
| Bourdin [25] |
Data are presented a n (%), unless otherwise stated. Ig: immunoglobulin; IL: interleukin; TNF-α: tumour necrosis factor-α; FeNO: fractional exhaled nitric oxide.