Psychometric evaluation of the Taiwanese version of the Kiddo-KINDL® generic children's health-related quality of life instrument

Background: Health-related quality of life measures are increasingly being used in evaluating health care outcome around the world. There is a demand for the development of quality of life measures to be used cross-culturally. The aim of this study is to evaluate the psychometric properties of the Taiwanese version of Kiddo-KINDL®, a health-related quality of life questionnaire. Methods: The original German-version of Kiddo-KINDL® was translated into Chinese (Taiwanese) via the forward/backward translation process. Psychometric testing was performed with a national sample of 1,985 healthy students between the ages of 12 and 16. Data were analyzed based on 1,675 usable questionnaires. Results: The reliability coefficients were α = 0.81 (overall) and -0.31 to 0.84 for six subscales. The subscales with low Cronbach's α were "school" and "friends." Test-retest reliability was 0.77. Convergent validity was examined with the broadly used Taiwanese version of the Adolescent Depressive Mood Self-Detecting Scale. The result was satisfactory. Construct validity was further examined with exploratory factor analysis. The six-factor solution explained 45.2% of the variance. The construct of Kiddo-KINDL® (Taiwanese version) appeared to be appropriate for measuring health-related quality of life in healthy adolescents. Conclusions: Kiddo-KINDL® (Taiwanese version) is a relatively reliable and valid questionnaire of adolescents' health-related quality of life. However, items in the "school" and "friends" subscales need to be further modified to be more culturally appropriate.