The validation of the Turkish version of Asthma Control Test

Abstract

Current guidelines focus more on levels of asthma control than on severity of asthma. The original version of the Asthma Control Test (ACT), a self-administered instrument to determine asthma control levels, was designed for English-speaking patients. More recently, the ACT has been translated into many languages and has been validated for many cultures, but this is the first study to evaluate the Turkish version. We aimed to evaluate the reliability, validity, and responsiveness of the Turkish version of the ACT among outpatients with asthma. This multicenter prospective study included 220 asthma patients in outpatient clinics in Turkey. The ACT was completed at admission (Visit 1), after 10 ± 2 days (Visit 2), and at 5 ± 1 weeks (Visit 3). At each visit, physicians assessed patients' asthma control levels. The Turkish version of the ACT showed an internal consistency reliability of 0.84 (Cronbach's alpha). Test-retest reliability was 0.85 in stable patients. There was a significant correlation between the ACT and physicians' assessments at admission (r = 0.68, p < 0.001). The AUC was 0.91, with a sensitivity of 89.06% and a specificity of 78.26% for a score of ≤19 for screening "uncontrolled" asthma. A minimally important difference of three points on the ACT was consistent with the GINA physician assessment scores between the baseline and the follow-up visits. The Turkish version of the ACT is a valid and reliable tool for assessing asthma control in patients in outpatient settings. The test may facilitate the designation of asthma patients' symptoms as either controlled or uncontrolled.