Objectives: The aim of this study was to investigate the psychometric properties of the Greek version of the Pediatric Quality of Life Inventory(TM) 4.0 (PedsQL(TM) 4.0) as a population health outcome measure.
Methods: After cultural linguistic validation, a cross-sectional study with the participation of 645 children (8-12 years old) and their primary caregivers was conducted in a nation-wide representative school-based sample to evaluate the psychometric properties of the measure.
Results: All PedsQL 4.0 scales showed satisfactory reliability, with Cronbach's alpha exceeding 0.70--except in self-reported Physical Functioning (alpha = 0.65). Test-retest stability intraclass correlation coefficients (ICCs) were above 0.60 in all subscales. No floor effects were detected in either the self-report or parent proxy versions. Ceiling effects ranged from 2.2% (self-report Total Score) to 31.1% (parent-report Social Functioning). Poor to moderate agreement between self report and proxy report was observed, especially for the younger age groups of children. Impact of gender, health status, and family affluence status were detected, as hypothesised from previous bibliography, with girls reporting lower health-related quality of life (HRQOL) than boys on the Emotional Functioning subscale, healthy children scoring significantly higher on all scales than those with chronic illnesses, and lower socioeconomic groups scoring significantly lower than higher socioeconomic groups. Factor analysis showed mainly comparable results with the original version.
Conclusions: Present results support the reliability and validity of the PedsQL 4.0 Greek version. The instrument could be a valuable tool in HRQOL measurement in school health care settings and population-based studies in Greek-speaking children, though it should be stressed that when possible, the child should be considered the first informant of his/her HRQOL.