Table 5.
Repeatability of capsaicin challenge test, objective cough frequency and cough severity over 6 weeks in participants with stable chronic obstructive pulmonary disease
| Week 1 | Week 6 | ICC | |
|---|---|---|---|
| Cough reflex sensitivity | |||
| C1 (μmol L−1) | 0.93 (2.89) | 2.04 (3.90) | 0.37 |
| C2 (μmol L−1) | 1.50 (3.14) | 3.05 (4.13) | 0.54 |
| C5 (μmol L−1) | 6.29 (8.44) | 10.20 (7.45) | 0.85 |
| 24-h cough monitoring* | |||
| Total cough count (coughs) | 124.7 (4.1) | 165.0 (2.6) | 0.86 |
| Total cough frequency (coughs h−1) | 5.1 (4.2) | 6.9 (2.5) | 0.85 |
| Awake cough count (coughs) | 101.5 (3.9) | 134.0 (2.4) | 0.70 |
| Awake cough frequency (coughs h−1) | 6.5 (3.9) | 8.4 (2.4) | 0.84 |
| Cough severity VAS (mm) | 37 (23) | 45 (30) | 0.56 |
Data presented as geometric mean (SD) or mean (SD)
ICC intraclass correlation coefficient, C1capsaicin concentration required to elicit 1 cough, C2 capsaicin concentration required to elicit 2 coughs, C5 capsaicin concentrations required to elicit 5 coughs, VAS visual analogue scale
*n = 9