Identifying uncontrolled asthma in children with the childhood asthma control test or exhaled nitric oxide measurement

Background: International guidelines highlight the importance of assessing asthma control status in children with asthma, and research on practical and objective instruments for assessing asthma control is ongoing.

Objective: To determine the role of the Childhood Asthma Control Test (C-ACT) and fractional concentration of exhaled nitric oxide (FeNO) in identifying children with not well-controlled asthma.

Methods: Children 6 to 11 years of age with asthma were enrolled in the study. They completed C-ACT and underwent FeNO and spirometric measurements during the monthly clinic visits. An asthma specialist assessed asthma control according to the gold standard Global Initiative for Asthma guideline and decided the treatment of the patients.

Results: Seventy-six children with a mean (SD) age of 8.7 (1.4) years were evaluated in the first visit, whereas 64 and 51 children were admitted for second and third visits, respectively. A C-ACT score of 22 or less had 69% sensitivity and 77% specificity in determining not well-controlled asthma, whereas an FeNO value of 19 ppb or higher had 61% sensitivity and 59% specificity in patients who completed 3 visits. Receiver operating characteristic curve analysis revealed that the C-ACT was better than FeNO for identifying patients with not well-controlled asthma (area under the curve, 0.79; P < .001 [C-ACT] vs .58, P = .10 [FeNO]) Results of multivariate generalized estimating equation analysis revealed that a C-ACT score of 22 or less (odds ratio, 8.75; 95% confidence interval, 4.35-17.59; P < .001) and an FeNO of 19 ppb or greater (odds ratio, 2.60; 95% confidence interval, 1.07-6.29; P = .03) were significant indicators for the presence of not well-controlled asthma.

Conclusion: The C-ACT is superior to FeNO in determining the control status of children with asthma and may be used as a complementary tool in clinical practice to detect children with not well-controlled asthma.