Psychometric Validation of the Weight and Emotions Scale (WES) in Adults with Obesity or Overweight

INTRODUCTION: Individuals with obesity or overweight experience a substantial socioemotional burden and lower quality of life. Existing patient-reported outcome (PRO) instruments do not adequately measure emotional functioning concepts important to individuals with obesity/overweight. This study describes the psychometric properties of the Weight and Emotions Scale (WES), a new PRO measure to evaluate emotional functioning in adults with obesity or overweight. METHODS: 120 adults completed two web-based surveys (baseline, week 2). Survey 1 comprised the 16-item WES, Control of Eating Questionnaire, Impact of Weight on Quality of Life-Lite Clinical Trials Version, Impact of Weight on Self-Perceptions Questionnaire, and Patient Global Impression of Severity (PGIS) 'Overall Emotional Impact of Weight.' Survey 2 included the WES and PGIS 'Overall Emotional Impact of Weight.' Factor structure, reliability, and validity of the WES were assessed. RESULTS: Exploratory factor analysis of the WES supported a two-factor structure as items loaded strongly (≥ 0.59) on factors corresponding to positive and negative feelings. The unidimensional framework was revised to include two WES domains ('Positive Feelings' [8 items] and 'Negative Feelings' [8 items]). The WES domain and total scores demonstrated excellent internal consistency (Cronbach's alpha ≥ 0.90) and good test-retest reliability (intraclass correlation coefficient: 0.87-0.89). Convergent validity of the WES was demonstrated via large correlations with the Impact of Weight on Quality of Life-Lite Clinical Trials Version 'Psychosocial' score and items, Impact of Weight on Self-Perceptions Questionnaire total score, and PGIS 'Overall Emotional Impact of Weight.' Known-groups validity was demonstrated via higher WES domain and total scores in participants who reported feeling good about their weight (PGIS 'Overall Emotional Impact of Weight'). CONCLUSION: The final version of the WES with 16 items is a reliable and valid PRO measure for assessing emotional functioning in individuals with obesity or overweight, with potential utility in observational studies, clinical trials, and clinical practice.