The Asthma Control Test, Japanese Version (ACT-J) as a Predictor of Global Initiative for Asthma (GINA) Guideline-Defined Asthma Control: Analysis of a Questionnaire-Based Survey

Abstract
The 2006 Global Initiative for Asthma (GINA 2006) guidelines emphasize the importance of evaluating the control rather than the severity of asthma. The Asthma Control Test (ACT) is well known to be an excellent tool for evaluating asthma control in the clinical setting. This study aimed to evaluate the ACT, Japanese version (ACT-J) as a predictor of asthma control as defined by the GINA 2006 guidelines in actual clinical practice. A cross-sectional analysis comparing the ACT-J score and GINA classification of asthma control among 419 patients of primary care physicians and specialists was performed using the data from a 2010 questionnaire-based survey conducted by the Niigata Asthma Treatment Study Group. The optimal cut-off point of the ACT-J score for predicting GINA-defined asthma control was 23, with ACT-J scores of ≥23 and ≤22 predicting controlled and uncontrolled asthma with area under the receiver operating characteristics curve values of 0.76 [95% confidence interval (CI): 0.72-0.81] and 0.93 [95% CI: 0.90-0.97], respectively. ACT scores of ≥23 and ≤22 are useful for identifying patients with controlled and uncontrolled asthma, respectively, as defined by GINA 2006, and the latter is more strongly predictive than the former. The reason for the higher cut-off point of the ACT-J relative to other versions of the ACT is unclear and warrants further investigation.