BODY-Q-7D Measures Consensus-Based Patient-Reported Outcomes for the Management of Obesity Treatment.

Abstract

A global multidisciplinary consensus initiative identified eight patient-reported outcome domains important in obesity care: self-esteem; physical, mental, and social health; eating; stigma; body image; and excess skin. Several of these domains are not represented in generic preference-based measures typically used in weight loss research. We developed the BODY-Q-7 Dimensions (BODY-Q-7D) to provide a valuation-ready framework for a preference-based instrument. Concepts from the BODY-Q were used to inform the development of items that covered the eight consensus initiative domains. Psychometric performance of the BODY-Q-7D was examined using an online international sample (i.e., Prolific). Content validity was established with 123 participants. The field test included 770 participants, of whom 269 completed a test-retest, and 599 completed a 3-month follow-up. Rasch Measurement Theory analysis reduced the BODY-Q-7D to 7 items. Items fit the Rasch model with ordered thresholds and structural independence. Reliability was > 0.80 across three reliability coefficients. Hypothesis-based tests of construct validity and responsiveness were supported with 22/28 (79%) and 12/16 (75%) tests accepted. The BODY-Q-7D demonstrated strong psychometric performance in a weight loss sample. The next phase of development is to elicit and model preference weights to assign utility values to each defined health state.