Evaluating the Serbian version of the KIDSCREEN quality-of-life questionnaires: reliability, validity, and agreement between children's and parents' ratings

Abstract

To evaluate the psychometric properties of the Serbian set of the KIDSCREEN questionnaires: KIDSCREEN-52, KIDSCREEN-27, and KIDSCREEN-10 index. The study included 330 children (8-18 years) and 314 parents. All completed the KIDSCREEN and KINDL questionnaires. Psychometric analyses included internal consistency reliability (Cronbach's coefficient), criterion, convergent and discriminant validity, and agreement between children and parents (the intraclass correlation coefficient-ICC). Cronbach's alpha of 0.7 and above was found for all except for the self-perception scale of the KIDSCREEN-52, being 0.58 for the child and 0.63 for the parent version. Correlations between similar scales in the KIDSCREEN and KINDL were substantial (ranging 0.45-65) and higher than correlations between theoretically different scales. Moderate to excellent agreement existed between children's and parents' ratings in all KIDSCREEN scales (ICC ranged 0.44-0.63), except for the moods and emotions from the longer (ICC = 0.34) and the social support and peers from the shorter version (ICC = 0.38). Levels of internal consistency reliability and validity of all KIDSCREEN questionnaires in Serbian are appropriate, as well as agreement between children's and parents' ratings.