The KIDSCREEN-27 quality of life measure for children and adolescents: psychometric results from a cross-cultural survey in 13 European countries

OBJECTIVE: To assess the construct and criterion validity of the KIDSCREEN-27 health-related quality of life (HRQoL) questionnaire, a shorter version of the KIDSCREEN-52. METHODS: The five-dimensional KIDSCREEN-27 was tested in a sample of 22,827. For criterion validity the correlation with and the percentage explained variance of the scores of the KIDSCREEN-52 instrument were examined. Construct validity was assessed by testing a priori expected associations with other generic HRQoL measures (YQOL-S, PedsQL, CHIP), indicators of physical and mental health, and socioeconomic status. Age and gender differences were investigated. RESULTS: Correlation with corresponding scales of the KIDSCREEN-52 ranged from r = 0.63 to r = 0.96, and r2 ranged from 0.39 to 0.92. Correlations between other HRQoL questionnaires and KIDSCREEN-27 dimensions were moderate to high for those assessing similar constructs (r = 0.36 to 0.63). Statistically significant and sizeable differences between physically and mentally healthy and ill children were found in all KIDSCREEN-27 dimensions together with strong associations with psychosomatic complaints (r = -0.52). Most of the KIDSCREEN-27 dimensions showed a gradient according to socio-economic status, age and gender. CONCLUSIONS: The KIDSCREEN-27 seems to be a valid measure of HRQoL in children and adolescents. Further research is needed to assess longitudinal validity and sensitivity to change

Testing the structural and cross-cultural validity of the KIDSCREEN-27 quality of life questionnaire

OBJECTIVES: The aim of this study is to assess the structural and cross-cultural validity of the KIDSCREEN-27 questionnaire. METHODS: The 27-item version of the KIDSCREEN instrument was derived from a longer 52-item version and was administered to young people aged 8-18 years in 13 European countries in a cross-sectional survey. Structural and cross-cultural validity were tested using multitrait multi-item analysis, exploratory and confirmatory factor analysis, and Rasch analyses. Zumbo's logistic regression method was applied to assess differential item functioning (DIF) across countries. Reliability was assessed using Cronbach's alpha. RESULTS: Responses were obtained from n = 22,827 respondents (response rate 68.9%). For the combined sample from all countries, exploratory factor analysis with procrustean rotations revealed a five-factor structure which explained 56.9% of the variance. Confirmatory factor analysis indicated an acceptable model fit (RMSEA = 0.068, CFI = 0.960). The unidimensionality of all dimensions was confirmed (INFIT: 0.81-1.15). Differential item functioning (DIF) results across the 13 countries showed that 5 items presented uniform DIF whereas 10 displayed non-uniform DIF. Reliability was acceptable (Cronbach's alpha = 0.78-0.84 for individual dimensions). CONCLUSIONS: There was substantial evidence for the cross-cultural equivalence of the KIDSCREEN-27 across the countries studied and the factor structure was highly replicable in individual countries. Further research is needed to correct scores based on DIF results. The KIDSCREEN-27 is a new short and promising tool for use in clinical and epidemiological studies