Is Bronchodilator Responsiveness Helpful in Differentiating Between Different Types of Obstructive Airway Disease?

We have been taught that patients with asthma have bronchodilator responsiveness, whereas patients with chronic obstructive pulmonary disease (COPD) have irreversible obstruction. Bronchodilator responsiveness has recently been redefined as an increase of >10% in forced expiratory volume in 1 second (FEV₁) or forced vital capacity (FVC) relative to the predicted value, at 10 to 15 minutes after administration of a quick-acting bronchodilator. Researchers examined the utility of evaluating bronchodilator responsiveness in an international cohort of patients with physician-diagnosed asthma or COPD.

Among 3500 adolescent and adult patients (age, ≥12), bronchodilator responsiveness was about 19% for asthma, 18% to 25% for COPD, and 23% to 30% fo…