Clinical factors affecting discrepant correlation between asthma control test score and pulmonary function

The Asthma Control Test (ACT) score is widely used in asthma clinics, particularly with the recent emphasis on achievement and maintenance of optimal asthma control. However, this self-assessment score does not always correspond with lung function parameters, leading to uncertainty about each patient's control status; therefore, we investigated the clinical characteristics that are associated with discrepant correlation between the ACT score and pulmonary function. The 252 adult asthmatic subjects were divided into 5 groups according to their changes in FEV1% predicted values and ACT scores between 2 consecutive visits three months apart. The data were retrospectively reviewed and several clinical variables were compared. Elderly, non-eosinophilic, non-atopic asthma patients were more likely to show paradoxical changes of pulmonary function and ACT score. Female patients were prone to report exaggerated changes of ACT score compared with baseline lung function and changes in FEV1 levels. This group was using more medications for rhinosinusitis. Male patients seemed less sensitive to changes in lung function. From these findings, we conclude that when assessing asthma control status, physicians should carefully consider patient age, gender, atopy status, blood eosinophil levels, and comorbidities along with their ACT scores and pulmonary function test results.