Table 1 Patients’ baseline characteristics (full analysis set for exacerbation)
Characteristic | N-acetylcysteine Group (N = 464) | Placebo Group (N = 460) |
|---|---|---|
Age—year | 62.5 ± 8.4 | 62.6 ± 8.0 |
Male sex —no. (%) | 414 (89.2) | 404 (87.8) |
Body mass index—kg/m2 | 22.7 ± 3.6 | 22.9 ± 3.4 |
Smoking status—no. (%) | ||
Never smoked | 71 (15.3) | 85 (18.5) |
Former smoking | 135 (29.1) | 109 (23.7) |
Current smoking | 258 (55.6) | 266 (57.8) |
Smoking index — pack-year | 44.0 ± 25.6 | 43.6 ± 28.4 |
Biomass use — no. (%) | 250 (53.9) | 258 (56.1) |
Occupational exposure history — no. (%) | 226 (48.7) | 246 (53.5) |
Family history of respiratory disease — no. (%) | 82 (17.7) | 73 (15.9) |
Respiratory medication for COPD — no. (%) | 75 (16.2) | 62 (13.5) |
LAMA alone | 37 (8.0) | 31 (6.7) |
ICS and LABA | 27 (5.8) | 24 (5.2) |
Traditional Chinese medicine | 7 (1.5) | 10 (2.2) |
Xanthine | 9 (1.9) | 3 (0.7) |
Asmeton | 3 (0.6) | 3 (0.7) |
LABA alone | 4 (0.9) | 0 (0.0) |
LABA and LAMA | 2 (0.4) | 1 (0.2) |
ICS alone | 1 (0.2) | 0 (0.0) |
COPD exacerbations in the previous year—no. (%) | 92 (19.8) | 108 (23.5) |
Spirometric values at baseline | ||
Before bronchodilator use | ||
FEV1—L | 1.98 ± 0.55 | 1.95 ± 0.55 |
FEV1 % of predicted value—% | 78.3 ± 16.7 | 78.1 ± 17.3 |
FVC—L | 3.32 ± 0.79 | 3.26 ± 0.76 |
FEV1/FVC—% | 59.6 ± 7.5 | 59.3 ± 7.9 |
After bronchodilator use | ||
FEV1—L | 2.08 ± 0.54 | 2.04 ± 0.54 |
FEV1 % of predicted value—% | 82.4 ± 15.8 | 82.0 ± 16.8 |
FVC—L | 3.41 ± 0.75 | 3.38 ± 0.74 |
FEV1/FVC—% | 60.7 ± 7.5 | 60.2 ± 7.7 |
Airflow reversibility—no. (%) | 69 (14.9) | 58 (12.6) |
GOLD stage‖—no. (%) | ||
Mild (stage 1) | 261 (52.3) | 238 (47.7) |
Moderate (stage 2) | 203 (47.8) | 222 (52.2) |
mMRC dyspnea scale score | ||
Mean score | 0.82 ± 0.78 | 0.80 ± 0.78 |
Distribution—no. (%) | ||
<2 | 392 (84.5) | 386 (83.9) |
≥2 | 72 (15.5) | 74 (16.1) |
CAT score | ||
Mean score | 8.1 ± 5.8 | 8.5 ± 6.1 |
Distribution—no. (%) | ||
<10 | 300 (64.7) | 279 (60.7) |
≥10 | 164 (35.3) | 181 (39.3) |
