The study aimed to evaluate the reliability and validity of the Thai version of the Pediatric Quality of Life Inventory™ 4.0 Core Scales (PedsQL) as a measure of health-related quality of life (HRQOL).
The PedsQL items were completed by 2,086 pupils aged 8–15 years and 1,914 parents from four schools, and 100 pediatric outpatients and 100 parents from a University Hospital. Test–retest reliability was conducted in a randomly selected of 150 pupils at a 1-month interval.
Internal consistency reliability for the Total Scale score (α = 0.84 self-report, 0.88 proxy-report), Physical Health Summary score (α = 0.76 self-report, 0.79 proxy-report), and Psychosocial Health Summary score (α = 0.74 self-report, 0.85 proxy-report) exceeded the minimum reliability standard of 0.70. School children had significantly higher mean HRQOL scores compared to those with chronic health conditions for all subscales with the mean differences of 3.1–12.4 for self-report (p < 0.03) and 7.7–15.6 for proxy-report (p < 0.001). Test–retest reliability showed intraclass correlation coefficients above 0.60 in all subscales (p < 0.001).
The Thai version of PedsQL had adequate reliability and validity and could be used as an outcome measure of HRQOL in Thai children aged 8–15 years.