ABSTRACT
BACKGROUND: Assessment of control is central to asthma management. The Asthma Control Test (ACT) and Global Initiative for Asthma (GINA) defined control are commonly used measures of asthma control. This study examined the agreement between the ACT and GINA defined control and determined the best cut-off point of ACT to predict GINA level of control. METHODS: It was a cross-sectional study of 82 consecutive [72% females, age 44 (IQR) 29-60 years] asthmatic patients in a tertiary teaching hospital. We compared ACT with GINA defined control using Cohen's kappa and receiver operating characteristics curve was computed to determine sensitivity and specificity. RESULTS: There was fair to moderate level of agreement between ACT and GINA defined control (kappa 0.34 to 0.46). To detect GINA-defined controlled asthma, the ACT cut-off point of =20 had a sensitivity of 81%, specificity of 74%, a positive predictive value of 52% and negative predictive value of 92%, with an area under the receiver operating characteristics curve(AUC) value of 0.82 [95% confidence interval (CI): 0.72-0.90]. ACT scores of = 19 predicted GINA-defined uncontrolled asthma with sensitivity of 87%, specificity of 51%, positive predictive value of 41%, negative predictive value of 91% with AUC values of 0.75 (95% CI: 0.75-0.84). CONCLUSION: In Nigerian asthmatics, ACT scores of =20 and =19 are useful for identifying patients with controlled and uncontrolled asthma respectively, as defined by GINA 2014 criteria. However, the former is more predictive than the latter.
