This study investigates the health-related quality of life of children and adolescents in Germany, using the internationally employed KINDL-R questionnaire for measuring the health-related quality of life of children and adolescents. In the National Health Interview and Examination Survey for Children and Adolescents (KiGGS) the parents of 14,836 children and adolescents aged 3-17 years completed the KINDL-R, as well as 6,813 children and adolescents (11-17 years old). The reliability (Cronbach's alpha = 0.85) and validity of the measurements using the KINDL-R were confirmed. The differences in health-related quality of life of children and adolescents from different social backgrounds and with different health statuses, which were to be expected on theoretical grounds, were demonstrated by the KINDL-R scores (size of effect "d" up to 1.52). The means and percentiles were calculated for the total sample as well as stratified by age group, sex, geographical region (East/West), migratory status and socio-economic status. The results of this study can be used as representative, normative data for the population of children and adolescents in Germany in general, as well as stratified for sociodemographic and socio-economic subpopulations, in order to interpret test scores on health-related quality of life (KINDL-R).
