Health related quality of life in children and adolescents: Reliability and validity of the Norwegian version of KIDSCREEN-52 questionnaire, a cross sectional study

Background: A number of health-related quality of life instruments for children and adolescents have been developed and used in European countries during recent years. However, few well-validated instruments have been translated into Norwegian. As part of a larger investigation about pain and health-related quality of life, the KIDSCREEN-52, a cross-cultural 10-scale questionnaire, was translated into Norwegian. The aim of this study was to examine psychometric properties of the first Norwegian version of KIDSCREEN, particularly reliability and construct validity. Methods: A cross-sectional study was carried out, and a cluster sample of 20 randomly selected schools was drawn. The final study sample encompassed 1123 children and adolescents, aged 8-18 years. Internal consistency reliability was assessed using Cronbach's alpha. Construct validity was examined by confirmatory factor analysis, and by analysing whether the KIDSCREEN scales correlated with comparable KINDL scales, another health-related quality of life instrument. The analyses were conducted using SPSS (16.0) and Lisrel (8.7). Results: The Cronbach's alpha value was above 0.80 for all KIDSCREEN scales, suggesting good internal consistency reliability for the instrument. Confirmatory factor analysis shows that most of the KIDSCREEN scales fit the data well. Fit statistics for the 10-factor model were satisfactory, although some scales displayed residual covariance. Several confirmatory factor analysis models were fitted to the data, and the model specified according to the 10-dimensional KIDSCREEN-52 measurement model with correlated first-order factors fitted the data well (RMSEA = 0.04; CFI = 0.99). The KIDSCREEN scales correlated sufficiently highly with comparable KINDL scales. Conclusions: The results of the present study indicate that the Norwegian version of the KIDSCREEN-52 seems to work well in a Norwegian context, and is a valid and reliable generic health-related quality of life instrument. It is considered appropriate for screening in the public health area, for example, in school health care. (C) 2010 Elsevier Ltd. All rights reserved.