Measuring the quality of life of children with cerebral palsy: comparing the conceptual differences and psychometric properties of three instruments.

AIM To compare the conceptual differences, internal consistency, and validity of the Cerebral Palsy Quality of Life Questionnaire for Children (CP QOL-Child), the Child Health Questionnaire (CHQ), and a European generic health-related quality of life (HRQOL) questionnaire (10-domain version; KIDSCREEN-10) for children with cerebral palsy (CP). METHOD Two hundred and four primary caregivers (185 females [91%], 19 males [9%]) of children with CP aged 4 to 12 years (mean 8 y 4 mo [SD 2.51]; 112 males [55%], 92 females [46%], Gross Motor Function Classification System level I=18%, II=28%, III=14%, IV=11%, V=28%) provided demographic data and completed the CP QOL-Child, CHQ, and KIDSCREEN-10. Fifty-four children with CP aged 9 to 12 years completed the CP QOL-Child and KIDSCREEN-10. RESULTS The KIDSCREEN-10 and CP QOL-Child were developed to measure general HRQOL and CP-specific QOL respectively, whereas the CHQ was developed to measure functional health and well-being. In terms of internal consistency, KIDSCREEN-10 (Cronbach's alpha=0.86) and CP QOL-Child (0.74-0.91) outperformed the CHQ (0.18-0.96). In terms of validity, all instruments were moderately correlated. Floor and ceiling effects, although minimal or not evident for KIDSCREEN-10 and CP QOL-Child (1-4.9%), were apparent for CHQ (0.5-62.9%). INTERPRETATION Conceptually and psychometrically, KIDSCREEN-10 and CP QOL-Child performed more strongly than the CHQ, for children with CP. The choice between these two instruments will depend on the questions posed and outcomes sought by the researcher or clinician.