MEASURING PATIENT PREFERENCES FOR BARIATRIC SURGERY: A DISCRETE CHOICE EXPERIMENT

Purpose:   Because uptake of bariatric surgery is low among eligible patients, we sought to quantify the relative importance of specific attributes of bariatric surgery and medical weight loss programs in treatment choices.

Method: A discrete choice experiment (DCE) was used to value preferences for attributes of bariatric surgery procedures. Attributes of the DCE were identified through 12 patient focus groups (n=93) and an expert stakeholder panel of bariatric program coordinators who were also previous bariatric surgery patients (n=12). Using thematic analysis, 9 attributes were identified as being most important to the consideration of weight loss treatment options, which included bariatric surgery and medical weight loss.  Attributes were: how treatment works, extensiveness, years treatment has been available, weight loss, resolution of medical conditions, risk of complications, side effects, diet changes, and out of pocket costs.  Profiles of hypothetical weight loss or bariatric surgery options were generated using a fractional factorial design.  Respondents were asked to select which option they would choose from pairs of hypothetical treatment profiles or an opt-out option.  Respondents were recruited from bariatric surgery information sessions in 2015. An effects coded conditional logit model was used to assess the relative importance of each attribute on choices. Latent class analysis was used to identify patient subgroups with distinct preferences.

Result: Respondents reflected the general population of bariatric surgery candidates with most between the ages of 30-59 and 80% women (n=815). Higher total weight loss, lower initial out-of-pocket cost, and resolution of medical conditions were strongly associated with a higher likelihood of selecting a profile.  How treatment works, risk of complications, side effects, and dietary changes were of lower significance. Latent class analysis revealed a group of respondents that was more sensitive to out-of-pocket costs and second group that was more sensitive to the weight and health effects of a procedure.

Conclusion: Prospective patients placed a high value on total weight loss, low initial out of pocket costs, and a resolution of their medical conditions, but did not place much consideration on risk of complications or side effects of available treatments.  One segment of patients was very sensitive to the out-of-pocket costs associated with available treatment options.