Objective: This study assesses the reliability and validity of the European KIDSCREEN-52 generic health-related quality of life (HRQoL) questionnaire for children and adolescents. Research Design: The KIDSCREEN-52, which measures HRQoL in 10 dimensions, was administered to a representative sample of 22,827 children and adolescents (8 to 18 years) in 13 European countries. Psychometric properties were assessed using the Classical Test Theory approach, Rasch analysis, and structural equation modeling (SEM). A priori expected associations between KIDSCREEN scales and sociodemographic and health-related factors were examined. Test-retest reliability was assessed in 10 countries. Results: For the overall sample, Cronbach's alpha values ranged from 0.77 to 0.89. Scaling success (Multitrait Analysis Program) was >97.8% for all dimensions and Rasch analysis item fit (INFITmsq) ranged from 0.80 to 1.27. The intraclass correlation coefficients ranged from 0.56 to 0.77. No sizeable differential item functioning (DIF) was found by age, sex or health status. Four items showed DIF across countries. The specified SEM fitted the data well (root mean square error of approximation: 0.06, comparative fit index: 0.98). Correlation coefficients between Pediatric Quality of Life Inventory, Child Health and Illness Profile-Adolescent Edition, and Youth Quality of Life Instrument scales and KIDSCREEN dimensions assessing similar constructs were moderate for those (r = 0.44 to 0.61). Statistically significant differences between children with and without physical and mental health problems (Children with Special Health Care Needs screener: d = 0.17 to 0.42, Strengths and Difficulties Questionnaire: d = 0.32 to 0.72) were found in all dimensions. All dimensions showed a gradient according to socioeconomic status. Conclusions: The KIDSCREEN-52 questionnaire has acceptable levels of reliability and validity. Further work is needed to assess longitudinal validity and sensitivity to change.
Objective: This study assesses the reliability and validity of the European KIDSCREEN-52 generic health-related quality of life (HRQoL) questionnaire for children and adolescents. Research Design: The KIDSCREEN-52, which measures HRQoL in 10 dimensions, was administered to a representative sample of 22,827 children and adolescents (8 to 18 years) in 13 European countries. Psychometric properties were assessed using the Classical Test Theory approach, Rasch analysis, and structural equation modeling (SEM). A priori expected associations between KIDSCREEN scales and sociodemographic and health-related factors were examined. Test-retest reliability was assessed in 10 countries. Results: For the overall sample, Cronbach's alpha values ranged from 0.77 to 0.89. Scaling success (Multitrait Analysis Program) was >97.8% for all dimensions and Rasch analysis item fit (INFITmsq) ranged from 0.80 to 1.27. The intraclass correlation coefficients ranged from 0.56 to 0.77. No sizeable differential item functioning (DIF) was found by age, sex or health status. Four items showed DIF across countries. The specified SEM fitted the data well (root mean square error of approximation: 0.06, comparative fit index: 0.98). Correlation coefficients between Pediatric Quality of Life Inventory, Child Health and Illness Profile-Adolescent Edition, and Youth Quality of Life Instrument scales and KIDSCREEN dimensions assessing similar constructs were moderate for those (r = 0.44 to 0.61). Statistically significant differences between children with and without physical and mental health problems (Children with Special Health Care Needs screener: d = 0.17 to 0.42, Strengths and Difficulties Questionnaire: d = 0.32 to 0.72) were found in all dimensions. All dimensions showed a gradient according to socioeconomic status. Conclusions: The KIDSCREEN-52 questionnaire has acceptable levels of reliability and validity. Further work is needed to assess longitudinal validity and sensitivity to change.