Table 1.
Subject characteristics
| Characteristic | No respiratory medication (n = 1,543) | One or more respiratory medications (n = 2,941) | p-value |
|---|---|---|---|
| Age (years) | 61.7 ± 8.8 | 63.8 ± 8.5 | <0.001 |
| Male sex (%) | 61.2 | 53.2 | <0.001 |
| Current smoker (%) | 58.8 | 35.2 | <0.001 |
| Smoking history (pack-years) | 47.6 ± 24.4 | 53.7 ± 28.1 | <0.001 |
| BMI (kg/m2) | 27.5 ± 5.3 | 28.1 ± 6.5 | 0.026 |
| FEV1 after BD use (% of predicted value) | 74.5 ± 17.2 | 48.5 ± 20.1 | <0.001 |
| GOLD severity (%) | <0.001 | ||
| 1 | 38.8 | 6.7 | |
| 2 | 52.2 | 38.0 | |
| 3 | 8.4 | 35.1 | |
| 4 | 0.6 | 20.3 | |
| GOLD group (%) | <0.001 | ||
| A | 66.1 | 10.1 | |
| B | 22.9 | 25.7 | |
| C | 4.6 | 5.1 | |
| D | 6.4 | 59.1 | |
| FEV1/FVC (%) | 61.3 ± 8.0 | 47.5 ± 13.2 | <0.001 |
| 6 MWT (ft) | 1452 ± 347 | 1115 ± 389 | <0.001 |
| mMRC dyspnea score | 0.8 ± 1.2 | 2.5 ± 1.3 | <0.001 |
| SGRQ score | 18.8 ± 17.2 | 46.4 ± 19.6 | <0.001 |
| BODE index | 0.9 ± 1.2 | 3.4 ± 2.0 | <0.001 |
| Exacerbation in the year before enrollment | |||
| Patient with exacerbation (%) | 13.5 | 56.2 | <0.001 |
| Exacerbation per patient | 0.27 ± 1.05 | 2.51 ± 3.97 | <0.001 |
| Patient with severe exacerbation (%) | 2.6 | 27.6 | <0.001 |
| Severe exacerbation per patient | 0.04 ± 0.32 | 0.56 ± 1.38 | <0.001 |
| CT measurements | |||
| % Emphysema | 5.5 ± 6.3 | 14.9 ± 13.3 | <0.001 |
| % Gas trapping | 23.6 ± 15.0 | 42.4 ± 20.6 | <0.001 |
| Subsegmental wall area (%) | 64.2 ± 2.5 | 65.8 ± 2.4 | <0.001 |
| Pi10 | 3.7 ± 0.1 | 3.7 ± 0.1 | <0.001 |
Data are presented as mean ± SD or %.
BD, bronchodilator; BMI, body mass index; CT, computed tomography; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global initiative for Chronic Obstructive Lung Disease; mMRC, modified Medical Research Council; Pi10, 10 mm luminal perimeter; SGRQ, St George's Respiratory Questionnaire; 6MWT, 6-minute-walk test.