Factor structure and measurement invariance of the Weight-Related Abuse Questionnaire (WRAQ).

Weight-related abuse is defined as verbal or physical maltreatment specific to one's weight. The Weight-Related Abuse Questionnaire (WRAQ) is an instrument specifically designed to measure weight-related abuse. The main goal of this research was to study the factor structure and measurement invariance of the Spanish version of the WRAQ in a non-clinical and a clinical sample. The clinical sample included 150 participants with obesity (60 % women) from the Hospital de Valme (Sevilla, Spain). The non-clinical sample included 301 students (79 % women) from the Spanish Open University (UNED). Scales to measure weight self-stigma and fear of gaining weight were used to analyze the convergent validity of the WRAQ. A confirmatory factor analysis showed that a two-factor model (verbal and physical abuse) was an acceptable fit for the data in both the clinical and non-clinical samples. Multigroup Confirmatory Factor Analysis revealed scalar measurement invariance by sample and gender. Cronbach's alpha coefficients and composite reliability for both samples were found to be good, with values ranging from 0.83 to 0.96. Fear of gaining weight was correlated to verbal (r = 0.36, p < .01) and physical (r = 0.12, p < .05) abuse, and weight self-stigma was also related to physical (r = 0.21, p < .01) and verbal (r = 0.41, p < .01) abuse. These results suggest that the WRAQ can be used in clinical and non-clinical samples to assess verbal and physical abuse in both men and women.