SUN-LB102 Development of a Conceptual Model to Present the Impacts of Obesity on Physical Functioning

Background. Obesity is a chronic disease with a significant negative impact on health-related quality of life (HRQoL) and specifically, physical functioning, including the ability to complete activities of daily living (ADLs). Weight loss based on lifestyle management (e.g. diet, exercise), surgery, and pharmacotherapy can improve physical functioning; however, there is a need for further qualitative research to support the content validity of patient-reported outcome (PRO) measures for use in clinical studies of obesity and thus inform regulatory decision-making. Objective. To explore the impacts of obesity on physical functioning and develop a conceptual model (a visual representation of the concepts of importance and relevance to the experience of living with obesity) to ultimately support the content validity of PRO measures.Methods. Qualitative semi-structured interviews were conducted in the United States with individuals who have overweight and obesity (Body Mass Index [BMI] ≥ 27.0 kg/m2) with a history of at least one unsuccessful dietary effort to lose body weight. Recruitment quotas targeted a sample with diverse demographic and clinical characteristics, including participants with and without diabetes. Experienced qualitative interviewers used open-ended questions to elicit spontaneous reports of the impact of obesity on individuals’ daily lives, and specific probing questions to explore impacts on physical functioning. Interviews were audio-recorded, transcribed and analyzed using thematic techniques. Results. A total of 33 participants were interviewed (mean BMI of 37.6 kg/m2 [27.4 kg/m2 to 56.6 kg/m2]; mean age of 45 years [19 to 81 years]). The sample included a mix of races (Caucasian: n=12, 36%), education completed (high school: n=17, 51%) and split of gender (female: n=16, 48%). During development of the conceptual model, two separate domains were identified to group the reported impacts on physical functioning: ‘Mobility/Movement’ and ‘ADLs’. The most frequently reported impacts related to Mobility/Movement were ‘running’ (n=31/33, 94%), ‘bending’ (n=27/33, 82%), ‘walking’ (n=26/33, 79%), ‘difficulty standing for prolonged periods’ (n=22/33, 67%), and ‘lifting’ (n=19/33, 58%). All participants reported effects on some aspect of physical functioning, which were often characterized in terms of their direct impact on ADLs such as ‘household chores’ (n=21/33, 64%). Conclusions. The conceptual model will serve as a basis to identify fit-for-purpose PRO measures with strong content validity to evaluate the impact of anti-obesity therapies on physical functioning in future clinical studies. Obesity has a consistent and significant impact on physical functioning, leading to limitations in various aspects of mobility and affecting an individual’s ability to carry out specific daily activities.