Asthma Control Test (ACT): Comparison with Clinical, Functional, and Biological Markers of Asthma Control

Abstract

Background. Asthma Control Test (ACT) is a simple tool for assessing the level of asthma control in clinical practice, and it has been validated in comparison with a general clinical assessment of asthma control, including forced expiratory volume in the first second (FEV1). Objective. To evaluate the relationship between ACT score and clinical and functional findings of asthma control and biomarkers of airway inflammation. Methods. A total of 68 asthmatic patients observed in our asthma clinic (33 regularly treated with inhaled corticosteroids (ICS) and 35 ICS-naïve) filled ACT questionnaire and underwent the following measurements: (a) FEV1 before and after salbutamol; (b) exhaled nitric oxide; (c) bronchial hyperresponsiveness to methacholine; (d) sputum eosinophil count; and (e) daytime and nighttime symptoms, rescue salbutamol, and twice-daily peak expiratory flow (PEF) recording on a 4-week diary card. Results. ACT score significantly correlated with symptom score, rescue medication use, and PEF variability, but not with FEV1, FEV1 reversibility, and markers of airway inflammation, which could not distinguish controlled from uncontrolled patients according to ACT, regardless of ICS treatment. Conclusion. ACT score is a valid tool to simply assess the current level of asthma control in terms of symptoms, rescue medication use, and PEF variability. Pulmonary function and biomarkers of airway inflammation are not related to the clinical asthma control as assessed by ACT and may represent additional measurements potentially useful in asthma management.