Measuring health-related quality of life in young children with physical illness: psychometric properties of the parent-reported KIDSCREEN-27

This study examined whether the KIDSCREEN-27 was reliable and valid in young children 2-7 years with chronic physical illnesses which included estimating inter-domain correlations and internal consistency; measurement invariance testing; and, discriminant and convergent validity assessments.Data come from the Multimorbidity in Children and Youth across the Life-course; a longitudinal study of individuals aged 2-16 years with physical illness. The parent-reported KIDSCREEN-27 was administered. Children (2-7 years; n = 106) were compared to adolescents (8-16 years; n = 157). Reliability was estimated using Cronbach α for internal consistency. Multiple group confirmatory factor analysis tested for measurement invariance. Cohen's d and Pearson coefficient were used to assess discriminant validity by sex and age. Convergent validity was tested using Pearson coefficients with the WHODAS 2.0 (child functioning/impairment). Multiple regression examined associations between multimorbidity (co-occurring physical and mental illness) and HRQL.Internal consistency reliabilities were α = 0.74-0.88 (children) and α = 0.77-0.88 (adolescents). Inter-domain correlations were relatively low (children: r = 0.18-0.59; adolescents: r = 0.30-0.62) indicating that each KIDSCREEN-27 domain was measuring a unique aspect of health-related quality of life. Measurement invariance was demonstrated (scalar level). Parameter estimates of the invariant models were similar for children and adolescents. Small, non-significant correlations were found for sex and age for children and adolescents. Medium, significant correlations were found for both groups between the KIDSCREEN-27 and WHODAS 2.0. Children and adolescents with multimorbidity had significantly lower physical well-being, psychological well-being, and school environment scores compare to those without multimorbidity. Regression coefficients were similar between groups.Findings provide evidence of adequate psychometrics for the KIDSCREEN-27 in young children with chronic physical illness.