Bronchodilator response as a hallmark of uncontrolled asthma: a randomised clinical trial.
INTRODUCTION
The goal of this study is to determine whether bronchodilator (BD) response can be used as a reliable measure of asthma control by analyzing the effects of a short course of oral corticosteroids (OC) or placebo (P) on spirometry, sputum cytology and BD response in controlled asthma patients scoring less than 1.5 on the ACQ5.


METHODS
Seventy patients with moderate to severe asthma who were undergoing combination therapy and were considered to be controlled based on ACQ5 scores, but who exhibited persistent positive BD response, were randomly assigned to two groups, one receiving OC and the other P. Patients were evaluated before and after 2 weeks of treatment. Intervention response (comparison of FEV(1) before and after OC or P treatment) was used as a measure of intervention efficacy, with values equal to or greater than 200 mL considered positive.


RESULTS
Patients who received OC showed significant improvement in FEV(1), and no longer exhibited a positive BD response. Those in the P group showed no change. In addition, sputum eosinophil counts significantly decreased in the OC group.


CONCLUSIONS
BD response can be used as a reliable measure of asthma control. This study suggests that ACQ5 scores alone are not sufficient to fully assess asthma control, and that BD response should be included as an essential measurement in any algorithm of asthma control evaluation.