Weight Loss and Outcomes in Wait-listed, Medically Managed, and Surgically Treated Patients Enrolled in a Population-based Bariatric Program Prospective Cohort Study

Background: Multidisciplinary bariatric care is increasingly being delivered in Canada within publicly funded regional programs. Demand is high, wait lists are long, and clinical effectiveness is unknown. Objective: To examine the "real-world" outcomes associated with a publicly funded, population-based regional bariatric (medical and surgical) program. Research Design: Prospective observational cohort. Subjects: Five hundred consecutive patients (150 wait-listed, 200 medically treated, 150 surgically treated) from the Edmonton Weight Wise program were enrolled. Measures: The primary outcome was weight change (kg). Between-group changes were analyzed using multivariable regression adjusted for age, sex, and baseline weight and "last-observation-carried-forward" was used for missing data. Subjects transitioning between groups (wait-list to medical or medical to surgery) were censored when crossing over. Results: At baseline, mean age was 43.7 +/- 9.6 years, mean body mass index was 47.9 +/- 8.1 kg/m(2), and 88% were female. A total of 412 subjects (82%) completed 2-year follow-up and 143 (29%) subjects crossed over to the next treatment phase. Absolute and relative (% of baseline) mean weight reductions were 1.5 +/- 8.5 kg (0.9 +/- 6.1%) for wait-listed, 4.1 +/- 11.6 kg (2.8 +/- 8.1%) for medically treated, and 22.0 +/- 19.7 kg (16.3 +/- 13.5%) for surgically treated (P < 0.001) subjects. For surgery, weight reductions were 7.0 +/- 9.7 kg (5.8 +/- 7.9%) with banding, 21.4 +/- 16.0 kg (16.4 +/- 11.6%) with sleeve gastrectomy, and 36.6 +/- 19.5 kg (26.1 +/- 12.2%) with gastric bypass (P < 0.001). Rates of hypertension, diabetes, and dyslipidemia decreased to a significantly greater degree with surgery than medical management (P < 0.001) and stayed the same or increased in wait-listed subjects. Conclusions: Population-based bariatric care, particularly bariatric surgery, was clinically effective. Weight and cardiometabolic risk was relatively stable wait-listed patients receiving "usual care."