Revisiting asthma control: How should it best be defined?

Management guidelines for asthma emphasize a stepwise approach in treating this disease based on daytime symptoms, nighttime symptoms, and lung function assessed by peak expiratory flow or forced expiratory volume at 1 s (FEV1). Although improvement of lung function is a key goal in managing asthma, clinicians often see patients who may have achieved a normal FEV1 with guideline-recommended treatment but continue to experience limitations in their daily activities. In such situations, focusing the assessment solely on pulmonary function (e.g. FEV1) is often inadequate and may lead to undertreatment. Alternate assessment measures are therefore often needed to assess asthma control and achieve a successful treatment outcome. This review will provide practical guidance relevant to the clinical assessment of asthma control.