Table 1.
Baseline Characteristics of Participants With GOLD Stage 0 Diseasea Categorized by Bronchodilator Responsiveness (n = 1,481)
| Characteristics at Visit 1 | ATS-BDR |
P Valueb | ||
|---|---|---|---|---|
| Never | Inconsistent | Consistent | ||
| No. of patients | 725 | 629 | 127 | . . . |
| Age, y | 62.7 ± 9.5 | 64.0 ± 8.9 | 63.5 ± 8.6 | .026 |
| Female sex | 334 (46.1) | 301 (47.9) | 51 (40.2) | .28 |
| White race | 547 (75.4) | 486 (77.3) | 108 (85.0) | .06 |
| BMI, kg/m2 | 28.7 ± 5.1 | 28.6 ± 5.2 | 28.6 ± 5.4 | .94 |
| Pack-years of smoking | 45.3 ± 26.4 | 48.3 ± 23.0 | 52.3 ± 22.8 | .004 |
| Current individuals who smoke | 288 (40.1) | 261 (42.4) | 61 (48.4) | .20 |
| Asthma | 91 (12.6) | 136 (21.6) | 27 (21.3) | < .001 |
| Childhood asthma | 33 (4.6) | 69 (11.0) | 12 (9.4) | < .001 |
| Bronchodilator | 186 (25.9) | 262 (42.1) | 61 (48.4) | < .001 |
| Inhaled corticosteroids | 106 (14.8) | 162 (26.0) | 37 (29.6) | < .001 |
| Before bronchodilator administration | ||||
| FEV1, L | 2.59 ± 0.70 | 2.09 ± 0.66 | 1.83 ± 0.55 | < .001 |
| FEV1 % predicted | 89.1 ± 16.4 | 74.18 ± 17.4 | 61.2 ± 13.0 | < .001 |
| FVC, L | 3.65 ± 0.96 | 3.27 ± 0.96 | 3.19 ± 0.94 | < .001 |
| FVC % predicted | 95.8 ± 14.9 | 87.8 ± 16.9 | 80.9 ± 15.3 | < .001 |
| FEV1 to FVC ratio | 92.53 ± 9.62 | 83.85 ± 10.66 | 75.63 ± 8.97 | < .001 |
| After bronchodilator administration | ||||
| FEV1, L | 2.70 ± 0.73 | 2.32 ± 0.68 | 2.23 ± 0.62 | < .001 |
| FEV1 % predicted | 93.1 ± 16.6 | 82.3 ± 17.0 | 74.9 ± 13.3 | < .001 |
| FVC, L | 3.69 ± 0.96 | 3.48 ± 0.98 | 3.65 ± 0.99 | < .001 |
| FVC% predicted | 96.7 ± 14.7 | 93.4 ± 15.9 | 92.8 ± 14.9 | < .001 |
| FEV1/FVC | 95.86 ± 9.97 | 87.60 ± 10.06 | 80.44 ± 7.00 | < .001 |
| Change in FEV1, mL | 120 ± 110 | 230 ± 180 | 410 ± 190 | < .001 |
| Change in FEV1, % | 4.7 ± 4.2 | 12.4 ± 11.4 | 23.7 ± 12.8 | < .001 |
| Change in FVC, mL | 40 ± 150 | 210 ± 240 | 460 ± 270 | < .001 |
| Change in FVC, % | 1.1 ± 4.1 | 7.2 ± 8.6 | 15.7 ± 9.8 | < .001 |
Data are presented as No. (%) or mean ± SD, unless otherwise indicated. We categorized tobacco-exposed participants with normal spirometry findings based on ATS-BDR into three groups: consistent BDR when it is present at every visit; inconsistent BDR when it is present at some, but not all, visits; and never BDR when it is not present at any visit. ATS-BDR = increase in FEV1, FVC, or both of ≥ 12% and ≥ 200 mL after bronchodilator administration according to the American Thoracic Society/European Respiratory Society guidelines; BDR = bronchodilator responsiveness.
Normal spirometry findings.
Analysis of variance or Kruskal-Wallis test for continuous variables and χ2 or Fisher exact test for categorical variables.