Feasibility, reliability and validity of the health-related quality of life instrument Child Health Utility 9D (CHU9D) among school-aged children and adolescents in Sweden

BACKGROUND: This study was conducted in a general population of schoolchildren in Sweden, with the aim to assess the psychometric properties of a generic preference-based health related quality of life (HRQoL) instrument, the Swedish Child Health Utility 9D (CHU9D), among schoolchildren aged 7–15 years, and in subgroups aged 7–9, 10–12 and 13–15 years. METHODS: In total, 486 school aged children, aged 7–15 years, completed a questionnaire including the CHU9D, the Pediatric quality of life inventory 4.0 (PedsQL), KIDSCREEN-10, questions on general health, long-term illness, and sociodemographic characteristics. Psychometric testing was undertaken of feasibility, internal consistency reliability, test–retest reliability, construct validity, factorial validity, concurrent validity, convergent validity and divergent validity. RESULTS: The CHU9D evidenced very few missing values, minimal ceiling, and no floor effects. The instrument achieved satisfactory internal consistency (Cronbach’s Alfa > 0.7) and strong test–retest reliability (r > 0.6). Confirmatory factor analyses supported the proposed one-factor structure of the CHU9D. For child algorithm, RMSEA = 0.05, CFI = 0.95, TLI = 0.94, and SRMR = 0.04. For adult algorithm RMSEA = 0.04, CFI = 0.96, TLI = 0.95, and SRMR = 0.04. The CHU9D utility value correlated moderately or strongly with KIDSCREEN-10 and PedsQL total scores (r > 0.5–0.7). The CHU9D discriminated as anticipated on health and on three of five sociodemographic characteristics (sex, age, and custody arrangement, but not socioeconomic status and ethnic origin). CONCLUSIONS: This study provides evidence that the Swedish CHU9D is a feasible, reliable and valid measure of preference-based HRQoL in children. The study furthermore suggests that the CHU9D is appropriate for use among children 7–15 years of age in the general population, as well as among subgroups aged 7– 9, 10–12 and 13–15 years.