Baseline characteristics
| Group A | Group B | t-value | Z-value | p-value | |
| Subjects n | 14 | 13 | |||
| Age years | 51.64±19.93 | 52.64±16.94 | −0.28 | 0.978 | |
| Sex male/female | 9/5 | 4/7 | |||
| Sputum volume mL·24 h−1 | 57.64±56.91 | 43.50±28.76 | 0.741 | 0.465 | |
| Purulent score | 6.14±1.16 | 6.23±0.73 | −0.233 | 0.818 | |
| Sputum viscosity | 2.14±0.77 | 2.36±1.00 | −0.473 | 0.640 | |
| FEV1 L | 1.64±0.76 | 1.63±0.59 | −0.035 | 0.972 | |
| FEV1 % predicted | 53.79±12.52 | 62.84±26.18 | −1.310 | 0.203 | |
| FVC L | 2.47±1.07 | 2.21±0.91 | 0.685 | 0.50 | |
| FVC % predicted | 66.43±13.78 | 68.94±21.68 | −0.419 | 0.679 | |
| FEV1/FVC % | 68.29±13.68 | 74.50±10.32 | −1.590 | 0.125 | |
| PEF L | 4.38±2.05 | 3.73±1.01 | 0.925 | 0.364 | |
| Inspiratory capacity L | 1.73±0.82 | 1.47±0.56 | 0.851 | 0.403 | |
| 6MWD m | 507.64±130.51 | 508.50±73.61 | 0.122 | 0.904 | |
| LCQ score | |||||
| Physical | 4.08±1.23 | 3.93±1.10 | 0.456 | 0.653 | |
| Psychological | 3.60±1.17 | 2.66±0.84 | 2.315 | 0.029 | |
| Social | 4.37±1.07 | 3.55±1.34 | 1.737 | 0.095 | |
| Total score | 12.12±2.95 | 10.15±2.87 | 1.779 | 0.087 | |
| Bacteria count of sputum ×104·mL−1 | 795.83±395.25 (n=12) | 836.42±550.75 (n=11) | −0.380 | 0.708 | |
| Sputum cell classification | |||||
| Neutrophils % | 94.83±8.09 | 96.28±3.58 | −0.412 | 0.680 | |
| Macrophages % | 2.96±7.41 | 1.56±2.96 | −0.908 | 0.364 | |
| Eosinophils % | 0.83±1.14 | 0.78±1.17 | −0.461 | 0.645 | |
| Lymphocytes % | 1.54±1.59 | 1.39±2.22 | −0.129 | 0.897 | |
| TNF-α ×103 pg·mL−1 | 1.91±2.25 (n=12) | 1.00±1.36 (n=5) | −0.949 | 0.343 | |
| IL-8 ×103 pg·mL−1 | 420.33±389.21 (n=11) | 184.56±107.42 (n=5) | −0.108 | 0.914 | |
| IL-6 ×103 pg·mL−1 | 0.52±0.82 (n=7) | 1.46±1.03 (n=5) | −1.218 | 0.223 |
Data are presented as n or mean±sd, unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PEF: peak expiratory flow; 6MWD: 6-min walk distance; LCQ: Leicester cough questionnaire; TNF: tumour necrosis factor; IL: interleukin.