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, 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."