Development and cross-sectional validation of the Childhood Asthma Control Test.

Abstract

For children younger than 12 years old with asthma, there are several quality-of-life instruments, clinical diaries, and questionnaires assessing symptoms; however, a validated tool for assessing asthma control is currently lacking. To develop and validate the Childhood Asthma Control Test (C-ACT), a self-administered tool for identifying children aged 4-11 years whose asthma is inadequately controlled. A 21-item questionnaire was administered to 343 patients with asthma and their caregivers, randomly assigning 75% (n = 257) for development and cross-sectional validation of the tool and 25% (n = 86) to a confirmatory sample. Stepwise logistic regression was used to reduce the 21 items to those best able to discriminate control as defined by the specialist's rating of asthma control. Seven items were selected from regression analyses of the development sample to comprise the C-ACT. The scores of each item were summed for a total score (0-27), with lower scores indicating poorer control. Summed scores discriminated between groups of patients differing in the specialists' rating of asthma control (F = 36.89; P < .0001), the need for change in patients' therapy (F = 20.07; P < .0001), and % predicted FEV(1) (F = 2.66; P = .0494). A score of 19 indicated inadequately controlled asthma (specificity 74%, sensitivity 68%). These analyses were confirmed in the confirmatory sample. The C-ACT is a validated tool to assess asthma control and identify children with inadequately controlled asthma. The C-ACT can be valuable in clinical practice and research based on its validation, ease of use, input from the child and caregiver, and alignment with asthma guidelines.