Psychometric Properties and Predictive Validity of the PP-ACT

Objective: The Parent Proxy Asthma Control Test (PP-ACT) is a self-report measure of asthma control completed by caregivers on behalf of a child. We examined the psychometric properties and the reliability and predictive validity of the PP-ACT. Methods: We conducted two studies (one cross-sectional, one longitudinal over three months) that surveyed caregivers (N = 1622) of children with asthma. Caregivers completed the PP-ACT and a variety of other measures, including child health outcomes. Results: We found clear evidence that the five-item PP-ACT assesses two distinct constructs: Items 1-4 (which we call the PP-ACT4) assess symptoms, impairment, and use of a short acting beta-2 blocker (albuterol); Item 5 assesses caregivers' global subjective assessment of their child's asthma control. In addition, the two constructs function as unique predictors of asthma outcomes. Both the PP-ACT4 and Item 5 predicted unique variance in ED visits, the number of symptom-free days, and child quality of life. Only the PP-ACT4 predicted frequency of ICS use and only at Time 1 in Study 1. Conversely, Item 5 predicted exacerbation frequency whereas the PP-ACT4 did not. Conclusion: Our findings suggest that researchers and clinicians should treat the PP-ACT4 and Item 5 as distinct indicators of asthma control because they differentially predict asthma outcomes and likely have distinct meanings to caregivers.