Effects of categorical variables on the annual FEV1 changes in stable patients with COPD (univariable analysis)
| Variables | p Value |
|---|---|
| Gender (male vs female) | 0.473 |
| History of frequent exacerbation (yes vs no) | 0.006 |
| GOLD stage (I/II/III/IV) | 0.009 |
| Long-term oxygen therapy (yes/no) | 0.128 |
| Use of inhaled corticosteroids (yes vs no) | 0.862 |
| Use of long-acting β agonists (yes vs no) | 0.861 |
Bold typeface indicates statistical significance.
COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; GOLD, Global Initiative for Chronic Obstructive Lung Disease.