Measuring quality of life in Japanese children: Development of the Japanese version of PedsQL

Background: Health-related quality of life (HRQL) is perceived as an important health-care outcome. There are several systems for measuring the HRQL in adults but there are few such systems for children in Japan. Pediatric Quality of Life Inventory (PedsQL) is valid and demonstrates excellent reliability in the USA, Europe, and Asian countries. The aim of the present study was therefore to develop the Japanese version of PedsQL. Methods: A two-step procedure was performed: translation of PedsQL, followed by examination of the psychometric properties in a cross-sectional study. The feasibility, reproducibility, internal consistency reliability, factor structure, and concurrent and clinical validity were examined. Results: The internal consistency reliability of the Child Self-Reports of young children was slightly low, but that of the Child Self-Reports of school children and adolescents was good. Further, all the Parent Proxy-Reports had excellent alphas. The Japanese version had satisfactory feasibility for all age ranges. The intercorrelation of subscales supported the multidimensional factor structure. Clinical validity was examined by analysis of variance performed for four groups with different health conditions (healthy, chronic needs only, mental condition only, and chronic needs and mental condition). The scores of each functioning scale differed among the four groups, with the healthy group having the highest scores for all functioning scales. Conclusions: The Japanese version of PedsQL can be applied in community and school health settings in Japan. Because children with chronic health needs and mental conditions were included, the Japanese version of PedsQL is expected to be useful in clinical settings.