The Dutch Body Shape Questionnaire among patients with binge-eating disorder: psychometrics and norms of the full version (BSQ34) and the short version (BSQ8C).

Purpose: This study examined the psychometric properties and provided normative data of the Dutch Body Shape Questionnaire (BSQ34) and its shortened BSQ8C among patients with binge-eating disorder.

Methods: The two versions of the BSQ were administered to patients with binge-eating disorder (N = 155) enrolled for treatment, and to a community sample (N = 333). The translation and back-translation of the BSQ were performed by translators with and without eating-disorder expertise. Internal consistency, concurrent validity, test-retest reliability, incremental validity, and sensitivity to change were determined. A receiver-operating-characteristic curve-analysis was used to establish criterion-related validity, for which the Eating Disorder Examination-Shape concern subscale, was used. Uni-dimensionality of the instrument was investigated with confirmatory factor analysis. Norms (population-based T-scores and clinical percentile-scores) were determined.

Results: The psychometric properties of the BSQs were satisfactory. The BSQ34 discriminated well in body-shape dissatisfaction between patients with binge-eating disorder and the community sample (area-under-the-curve value = 0.91-0.98) and had a unidimensional factor structure. Comparing structural invariance between both samples revealed that scaler invariance was not supported, indicating that items may be interpreted differently by patients with binge-eating disorder and subjects from the community. Analyses were repeated for the BSQ8C, which yielded similar results.

Conclusion: The results indicated that both versions of the BSQ appeared suitable to screen for body-shape dissatisfaction among patients with binge-eating disorder. The BSQ34 supplies valuable information on the various types of concerns respondents have, which are critical to consider in clinical settings; the BSQ8C is recommended as a short screening tool.

Level of evidence: Level III: Evidence obtained from well-designed cohort or case-control analytic studies.