| Criteria | Reasoning |
| COPD stage IV, FEV1 <1.0 L, LTOT and age >75 yrs | Increased risk for bronchoscopy adverse events |
| Oral glucocorticoids | May attenuate inflammation |
| Active smokers | Induces acute inflammation |
| Frequent severe exacerbations | May interfere with CT and bronchoscopy |
| Age <45 yrs, <5 pack-yrs | Other causes likely |
| >80 pack-yrs | Low susceptibility to COPD |
| α1-AT, IgG deficiency | Will mimic COPD phenotype |
| Post-bronchodilator FEV1 increase >400 mL | Asthma as cause of fixed obstruction |
| Serious comorbidities and anti-coagulation treatment | Precludes bronchoscopy |
| Cardiac pacemaker implants | Generates CT artefacts |
| Major lung surgery | Lung function test and CT is distorted |
COPD: chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 s; LTOT: long-term oxygen therapy; α1-AT: α1-antitrypsin; IgG: immunoglobulin G; CT: computed tomography.