Assessing weight-related quality of life in adolescents

The development of a new weight-related measure to assess quality of life in adolescents [Impact of Weight on Quality of Life (IWQOL)-Kids] is described.

Using a literature search, clinical experience, and consultation with pediatric clinicians, 73 items were developed, pilot tested, and administered to 642 participants, 11 to 19 years old, recruited from weight loss programs/studies and community samples (mean z-BMI, 1.5; range, -1.2 to 3.4; mean age, 14.0; 60% female; 56% white). Participants completed the 73 items and the Pediatric Quality of Life Inventory and were weighed and measured.

Four factors (27 items) were identified (physical comfort, body esteem, social life, and family relations), accounting for 71% of the variance. The IWQOL-Kids demonstrated excellent psychometric properties. Internal consistency coefficients ranged from 0.88 to 0.95 for scales and equaled 0.96 for total score. Convergent validity was demonstrated with strong correlations between IWQOL-Kids total score and the Pediatric Quality of Life Inventory (r = 0.76, p < 0.0001). Significant differences were found across BMI groups and between clinical and community samples, supporting the sensitivity of this measure. Participants in a weight loss camp demonstrated improved IWQOL-Kids scores, suggesting responsiveness of the IWQOL-Kids to weight loss/social support intervention.

The present study provides preliminary evidence regarding the psychometric properties of the IWQOL-Kids, a weight-related quality of life measure for adolescents. Given the rise of obesity in youth, the development of a reliable and valid weight-related measure of quality of life is timely.