Development and initial validation of an obesity-specific quality-of-life measure for children: sizing me up.

The present study describes the development and initial validation of a new obesity-specific, self-report measure of health-related quality of life (HRQOL) for children aged 5-13 years. Participants included 141 obese children (mean age=9.2 years, 67% female, 55% black, mean zBMI=2.52) and their primary caregivers. Children completed Sizing Me Up (obesity-specific HRQOL) and the PedsQL (generic HRQOL). Item content for Sizing Me Up was based on the published child obesity and HRQOL literatures and expert opinion. Items use phrasing to orient children to respond to questions in context of his/her size (e.g., "were teased by other kids because of your size"). Caregivers completed Sizing Them Up, a parallel parent-proxy, obesity-specific HRQOL measure. Initial psychometric evaluation of Sizing Me Up was completed by conducting a factor analysis and determining internal consistency, test-retest reliability, and convergent and construct validity. Sizing Me Up is a 22-item measure with five scales (i.e., Emotional Functioning, Physical Functioning, Social Avoidance, Positive Social Attributes, and Teasing/Marginalization) that account for 57% of the variance and a total HRQOL score. Internal consistency coefficients range from 0.68 to 0.85. Test-retest reliabilities range from 0.53 to 0.78. Good convergent validity was demonstrated with the PedsQL (rs=0.35-0.65) and the parent-proxy Sizing Them Up (rs=0.22-0.44). Sizing Me Up represents the first obesity-specific HRQOL measure developed specifically for younger school-aged children (aged 5-13 years) with preliminary evidence of strong psychometric properties that likely has both clinical and research utility in a variety of settings.