Objective: There are few health-related quality of life (HRQOL) instruments available that have been validated for use with Turkish children. The Kid-KINDL is a generic measure of children's (8-12 years) HRQOL, which contains 24 categorical items that assess 6 dimensions (physical well-being, emotional well-being, self-esteem, family, friends, and school). The Kid-KINDL is available in many languages. Following an elaborate translation procedure and cognitive focus group interviews, the Kid-KINDL was adopted into Turkish. This paper describes the psychometric properties of the new Turkish Kid-KINDL.
Methods: In total, 1918 children aged 8-12 years at a school in Manisa completed the Kid-KINDL. A confirmatory approach was used for validity and reliability analysis. Using the Multi-trait/Multi-item analysis program (MAP) item-internal consistency and item-discriminant validity were calculated to confirm the instrument's structure. Likert scaling assumptions were tested and confirmatory factor analysis (CFA) was applied as well. After modification of 2 unsatisfactory items the Kid-KINDL was administered to a different group of 84 randomly selected children and the analyses were repeated.
Results: Cronbach's alpha was 0.35-0.78 before and 0.54-0.78 after the scales was modified. MAP-scaling success was 60%-100% before and 90%-100% after the modification. CFA confirmed the Kid-KINDL structure for the original version (RMSEA = 0.077) was less than the modified version (RMSEA = 0.059), although for the latter the sample was rather small. Floor effects were negligible, and ceiling effects reached 19%.
Conclusion: The results indicate that the Turkish Kid-KINDL was a reliable and factorially valid assessment of the children's HRQOL. The modifications made to the 2 unsatisfactory items increased the psychometric quality of the scale.