Reliability and Validity of the Turkish Version of a Self-Reported Sizing Me Up and a Parent-Proxy Sizing Them Up: Obesity Specific Health- Related Quality of Life Measures.

Abstract

Objective: Investigating the validity and reliability of the Turkish versions of the obesity-specific health-related quality of life perception scales for children and parents , Sizing Me Up/Sizing Them Up (SMU/STU), was the aim of this study. Materials and Methods: Sizing me up/sizing them up were translated into Turkish following a standardized translation procedure. Test-retest reliability, internal consistency, discriminant and convergent validity, as well as confirmatory factor analysis (CFA) were all assessed. Results: Sizing me up /sizing them up had a total scale Cronbach's alpha of 0.873, 0.872. In the test-retest evaluations, significant correlation was found in the SMU (except the Teasing/ Marginalization subscale), while no correlation was found in the Physical Functioning, Teasing/ Marginalization, School and Mealtime Difficulties subscales in the STU. The Pediatric Quality of Life Generic Core Scales (PedsQL) total mean score and the SMU/STU total mean scores exhibited a significant correlation (r=0.671, P < .0001/r=0.663, P < .001). Regarding the SMU total scale score and other subscale scores, excluding the Social Avoidance subscale, and the STU total scale score and other subscale scores, excluding Mealtime and School Functioning, a significant difference was found between the OB and non-OB samples. In CFA, the com- parative fit index (CFI) and root mean square error of approximation (RMSEA) values were not compatible with the expected values. Conclusion: The results demonstrated that both scales are suitable for use in the Turkish context and showed the validity and reliability of the Turkish versions of the SMU/STU; however, some inconsistencies were found in the items related to social avoidance in the SMU scale and posi- tive social attributes, mealtime challenges, and school functioning in the STU, so it is recom- mended that these items should be interpreted separately and carefully when evaluating scale scores by researchers or clinicians.