Psychometric properties of the KINDL-R questionnaire: results of the BELLA study

Background The concept of health-related quality of life (HRQoL) involves the respondents' perception of well-being and functioning in physical, emotional, mental, social, and everyday life areas. Research in the area of subjective health has resulted in the development of a multitude of HRQoL instruments that meet satisfying psychometric standards with regard to reliability, validity, and sensitivity of the scales. One frequently used generic measure for children and adolescents is the KINDL-R questionnaire developed by Ravens-Sieberer and Bullinger (Qual Life Res 7: 399-407, 1998). Methods Within the representative sample of the BELLA study, analyses regarding psychometric properties (namely reliability as well as discriminant and construct validity) are performed. Results Psychometric testing of the KINDL-R questionnaire reveals good scale utilisation and scale fit as well as moderate internal consistency. Correlations with the KIDSCREEN-52 subscales are shown. Differences in KINDL-R scores exist between chronically ill and healthy children as well as between SDQ problem scores. Conclusion The KINDL-R is a suitable instrument for measuring HRQoL in children and adolescents through self-report. The testing of the instrument in a representative sample of German children and adolescents as well as their parents provides reference values extending the potential of the KINDL-R questionnaire.