Table 1.
Baseline characteristics of patients with COPD according to the occurrence of exacerbation during a 1-year period
| Characteristic | Total | With exacerbation | Without exacerbation | P-value |
|---|---|---|---|---|
| Gender, M/F | 170/13 | 62/2 | 108/11 | 0.105 |
| Age (y) | 71.4 ± 8.7 | 72.5 ± 9.1 | 70.8 ± 8.5 | 0.229 |
| FEV1 (L) | 1.50 ± 0.64 | 1.27 ± 0.66 | 1.63 ± 0.61 | <0.001 |
| FEV1% predicted (%) | 55.7 ± 20.7 | 47.8 ± 18.1 | 59.9 ± 20.9 | <0.001 |
| %DLco/VA (%) | 59.2 ± 22.8 | 53.9 ± 20.3 | 62.0 ± 23.5 | 0.002 |
| LTOT use (%) | 40.4 | 62.5 | 37.5 | <0.001 |
| PaO2 (torr) | 80.1 ± 12.1 | 82.6 ± 14.1 | 79.9 ± 10.9 | 0.166 |
| PaCO2 (torr) | 41.9 ± 5.2 | 42.8 ± 5.1 | 41.4 ± 5.3 | 0.113 |
| Current smoking (%) | 4.4 | 4.7 | 4.2 | 0.575 |
| Smoking pack-years | 75.6 ± 45.3 | 82.1 ± 47.1 | 72.1 ± 44.1 | 0.159 |
| GOLD stage I/II/III/IV (n) | 25/78/62/18 | 6/17/31/10 | 19/61/31/8 | 0.001 |
| BMI (kg/m2) | 22.2 ± 3.1 | 21.9 ± 2.5 | 22.4 ± 3.4 | 0.235 |
| FFMI (kg/m2) | 17.0 ± 1.7 | 16.7 ± 1.4 | 17.1 ± 1.8 | 0.116 |
| 6MWD (m) | 464.1 ± 111.9 | 436.7 ± 107.1 | 478.6 ± 112.1 | 0.016 |
| MMRC dyspnea scale | 1.3 ± 1.0 | 1.6 ± 1.0 | 1.1 ± 0.9 | 0.001 |
| LAA% | 34.1 ± 14.8 | 38.7 ± 14.4 | 31.6 ± 14.5 | 0.002 |
| WA% | 53.9 ± 12.5 | 55.4 ± 11.5 | 53.1 ± 13.0 | 0.237 |
| Charlson index | 2.6 ± 1.0 | 2.6 ± 0.9 | 2.6 ± 1.0 | 0.84 |
| BODE index | 2.4 ± 2.2 | 3.1 ± 2.2 | 2.1 ± 2.1 | 0.001 |
| ADO index | 4.0 ± 1.7 | 4.5 ± 1.7 | 3.7 ± 1.6 | 0.001 |
| DOSE index | 1.3 ± 1.4 | 2.1 ± 1.5 | 0.9 ± 1.2 | <0.001 |
| Previous exacerbation rate | 0.57 ± 0.98 | 1.13 ± 1.28 | 0.28 ± 0.58 | <0.001 |
Note: Data are expressed as means ± SD except where otherwise noted.
Abbreviations: 6MWD, 6-minute walking distance; ADO, age/dyspnea/airflow obstruction; BMI, body mass index; BODE, body mass index/airflow obstruction/dyspnea/exercise capacity; COPD, chronic obstructive pulmonary disease; DLco/VA, diffusing capacity of the lung for carbon monoxide and alveolar volume ratio; DOSE, dyspnea/airflow obstruction/smoking status/exacerbation frequency; FEV1, forced expiratory volume in 1 second; FFMI, fat-free mass index; GOLD, Global initiative for chronic Obstructive Lung Disease; LAA%, percentage of low-attenuation area; LTOT, long-term oxygen therapy; MMRC, Modified Medical Research Council dyspnea scale; Previous exacerbation, exacerbation of COPD within the previous year; SD, standard deviation; WA%, percentage of airway wall area.