A parent-child dyad approach to the assessment of health status and health-related quality of life in children with asthma.
Ungar WJ., Boydell K., Dell S., Feldman BM., Marshall D., Willan A., Wright JG.
Assessment of health state and health-related quality of life (HR-QOL) are limited by a child's age and cognitive ability. Parent-proxy reports are known to differ from children's reports. Simultaneous assessment using a parent-child dyad is an alternative approach.Our objective was to assess the validity, reliability and responsiveness of a parent-child dyad approach to utility and HR-QOL assessment of paediatric asthma health states.The setting was specialist care in a hospital-based asthma clinic. Participants were 91 girls and boys with asthma aged 8 to 17 years and 91 parents. The intervention employed was parent-child dyad administration of the Health Utilities Index (HUI) 2 and 3, the Pediatric Quality of Life Inventory™ (PedsQL™) Core and Asthma modules, and the Pediatric Asthma Quality of Life Questionnaire (PAQLQ). Questionnaires were administered by interview to children and parents separately and then together as a dyad to assess the child's health state. The dyad interview was repeated at the next clinic visit. Dyad-child agreement was measured by intra-class correlation (ICC) coefficient; Spearman correlations were used to assess convergent validity. Test-retest reliability was assessed in 28 children who remained clinically stable between visits with a two-way ICC coefficient. Responsiveness to change from baseline was assessed with Spearman coefficients in 30 children who demonstrated clinical change between visits.There was no significant agreement between parent and child for the HUI2 or HUI3 whereas agreement between dyad and child was 0.55 (95% confidence interval [CI] 0.36, 0.69) for the HUI2 and 0.74 (95% CI 0.61, 0.82) for the HUI3 overall. With respect to dyad performance characteristics, both HUI2 and HUI3 overall scores demonstrated moderate convergent validity with the generic PedsQL™ Core domains (range r = 0.30-0.52; p < 0.01). Dyad HUI2 attributes demonstrated moderate convergent validity with the generic PedsQL™ Core domains of similar constructs (range r = 0.35-0.43; p < 0.001) and weaker convergent validity with disease-specific domains (range r = 0.13-0.32). Dyad HUI3 attributes demonstrated weaker convergent validity compared with the HUI2. For the assessment of test-retest reliability, significant agreement between baseline and follow-up was observed for dyad HUI2 total (r = 0.53), dyad PedsQL™ Core summary (r = 0.70) and select dyad disease-specific domains. Significant responsiveness (r > 0.4; p < 0.05) was observed for dyad HUI2 total score change over time as correlated with dyad HUI3, dyad PedsQL™ Core summary and select disease-specific domains.The parent-child dyad approach demonstrated moderate to strong performance characteristics in generic and disease-specific questionnaires suggesting it may be a valuable alternative to relying on parent proxies for assessing children's utility and HR-QOL. Future research in additional paediatric populations, younger children and a population-based sample would be useful.