Table 1
Characteristics and outcomes in healthy controls and patients with chronic cough
| Chronic cough | p values (ANOVA, Kruskal-Wallis test or χ2 test) | ||||||
|---|---|---|---|---|---|---|---|
| Healthy controls (n = 16) | Asthma (n = 13) | PND/rhinitis (n = 7) | GOR (n = 5) | Bronchiectasis (n = 5) | Unidentified cause (n = 20) | ||
| Data are expressed as mean (SD) or median (range). | |||||||
| *p = 0.03, p = 0.01, **p = 0.005, ††p = 0.003 v control. | |||||||
| ‡p = 0.03, §p = 0.01, ||p = 0.04 v patients with asthma. | |||||||
| PND = postnasal drip; GOR = gastro-oesophageal reflux; ICS = inhaled corticosteroids; NCS = nasal corticosteroids; LABA = long acting β agonists; PPI = proton pump inhibitors; FEV1 = forced expiratory volume in 1 second; C2, C5 = lowest concentration of capsaicin that induced ⩾2 or ⩾5 coughs, respectively; EBC = exhaled breath condensate. | |||||||
| Age (years) | 43 (8) | 44 (17) | 55 (7)* | 59 (5)†,‡ | 62 (18)†,‡,§ | 53 (12)†,|| | 0.005 |
| M/F | 4/12 | 6/7 | 0/7 | 1/4 | 1/4 | 3/17 | 0.23 |
| Duration of cough (years) | – | 5.4 (5.5) | 11.4 (8.3) | 9.8 (5.5) | 10.7 (5.1) | 13.0 (7.8) | 0.08 |
| Patients on medication | – | 3 (2 ICS, 1 ICS + LABA) | 3 (2 NCS, 1 nasal anticholinergic) | 1 (PPI) | 0 | 6 (2 NCS, 2 oral antihistamine, 1 NCS + PPI, 1 ICS + PPI) | 0.54 |
| FEV1 (% predicted) | 100 (12) | 91 (16) | 88 (20) | 106 (18) | 98 (24) | 101 (20) | 0.27 |
| C2 (μM) | 7.8 (0.98–500) | 3.9 (0.98–250) | 0.98 (0.98–15.6) | 0.98 (0.98–1.95) | 3.9 (0.98–125) | 1.47 (0.98–31.3) | 0.13 |
| C5 (μM) | 125 (1.95–>500) | 31.3 (0.98–250) | 3.9 (0.98–15.6)** | 1.95 (0.98–15.6)†† | 3.9 (0.98–500) | 2.93 (0.98–>500)†† | 0.009 |
