Demographic and procedural characteristics in the different study groups
| Variable | COPD | Asthma | Control | Comparison between COPD and control group, two-sided. |
| n=122 | n=16 | n=101 | ||
| Female sex | 44.3% | 56.3% | 42.6% | p=0.80 |
| Age, years (SD) | 67.4 (7.3) | 65.5 (12.6) | 65.7 (7.9) | p=0.11 |
| Body mass index (SD) | 26.6 (4.7) | 25.1 (2.9) | 26.7 (3.8) | p=0.81 |
| Smoking status | p≤0.01 | |||
| Daily | 23.8% | 0.0% | 24.8% | |
| Ex-smokers | 75.4% | 75.0% | 58.4% | |
| Never | 0.8% | 25.0% | 16.8% | |
| FEV1/FVC ratio (SD) | 0.46 (0.13) | 0.67 (0.09) | 0.74 (0.05) | p≤0.01 |
| FEV1 % of predicted (SD) | 56.1 (19.7) | 90.7 (13.3) | 103.9 (12.4) | p≤0.01 |
| GOLD | ||||
| I | 8.2 % | – | – | |
| II | 50.8 % | – | – | |
| III | 24.6 % | – | – | |
| IV | 16.4 % | – | – | |
| CAT score ≥10 | 79.5% | 68.8% | 26.7% | p≤0.01 |
| PaO2 (SD)* | 9.6 (1.2) | 10.8 (1.1) | 11.1 (1.1) | p≤0.01 |
| PaCO2 (SD)* | 5.2 (0.5) | 4.95 (0.3) | 5.2 (0.5) | p=0.31 |
| Exacerbation ≥2 prev. year† | 17.2% | 6.25% | – | |
| Dread of procedure (SD)‡ | 4.0 (2.8) | 3.5 (2.4) | 3.3 (2.6) | p=0.07 |
| Received alfentanil sedation | 90.2% | 100% | 83.2% | p=0.122 |
| Total lidocaine dose, mg (SD) | 475 (54) | 479 (58) | 458 (45) | p=0.01 |
| BAL performed | 78.7% | 87.5% | 96.0% | p≤0.01 |
| Biopsies performed | 39.3% | 87.5% | 37.6% | p=0.79 |
| Less experienced bronchoscopist | 63.1% | 43.8% | 59.4% | p=0.57 |
Dread of procedure was rated on a 0–10 scale, with 0 representing no dread and 10 worst dread.
*Three missing values (one control, two COPD).
†Five missing values (one COPD, four asthma).
‡20 missing values (11 COPD, eight controls, one asthma).
BAL, bronchoalveolar lavage; CAT, COPD assessment test; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume after 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Lung Disease stage; PaCO2, partial pressure of carbon dioxide; PaO2, partial pressure of oxygen; prev, previous.