Development and Validation of New BODY-Q Scales Measuring Expectations, Eating Behavior, Distress, Symptoms, and Work Life in 4004 Adults From 4 Countries

Purpose The BODY-Q is a rigorously developed patient-reported outcome measure (PROM) for patients seeking treatment for obesity and body contouring surgery. A limitation of the uptake of the BODY-Q in weight management treatments is the absence of scales designed to measure eating-specific concerns. We aimed to develop and validate 5 new BODY-Q scales measuring weight loss expectations, eating behaviors, distress, symptoms, and work life. Material and Methods In phase 1 (qualitative), patient and expert input was used to develop and refine the new BODY-Q scales. In phase 2 (quantitative), the scales were field-tested in bariatric and weight management clinics in the United States (US), The Netherlands, and Denmark between June 2019 and January 2020. Data were also collected in the US and Canada in September 2019 through a crowdworking platform. Rasch measurement theory (RMT) analysis was used for item reduction and to examine reliability and validity. Results The new BODY-Q scales were refined through qualitative input from 17 patients and 20 experts (phase 1) and field-tested in 4004 participants (phase 2). All items showed ordered thresholds and good fit to the Rasch model. The RMT analysis provided evidence of reliability, with PSI values ≥0.72, Cronbach alpha values ≥0.83, and test-retest values ≥0.79. Better scores on 4 scales (exception expectations scale) correlated with lower BMI, with the strongest correlation between the eating-related distress scale scores and BMI (r= −0.249, P < 0.001). Conclusion The new BODY-Q scales can be used in research and clinical practice to assess weight loss treatments from the patient perspective. Graphical abstract