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

Abstract

Background: 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.

Objective: 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.

Methods: 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.

Results: 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.

Conclusion: The C-ACT is a validated tool to assess asthma control and identify children with inadequately controlled asthma.

Clinical implications: 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.