Introduction: We conducted a technology assessment to summarize and appraise the current evidence regarding the effectiveness and safety of bariatric surgery in the Medicare-eligible population.
Data Sources: We searched six bibliographic databases and the reference lists of published clinical practice guidelines, relevant narrative and systematic reviews, and scientific information packages from manufacturers and other stakeholders on the outcomes and prediction models of different bariatric procedures studied in the Medicare-eligible population.
Results: Of 126 eligible studies, 83 described outcomes after bariatric therapy and 43 described predictors of body weight loss or absolute body weight after bariatric therapy. We did not identify any randomized clinical trials in the Medicare-eligible population. Studies examined surgical modalities. There were no studies on endoscopically-performed bariatric procedures. Only 15 studies had a design and/or analytical approach that allowed inferences for causal treatment effects on weight loss outcomes, adverse events/complications, or other non-weight-loss outcomes. Bariatric surgery in the Medicare-eligible population leads to improvements in weight loss and non-weight-loss outcomes, particularly mortality, metabolic, cardiovascular, respiratory, and musculoskeletal outcomes, and polypharmacy but the strength of evidence is low to moderate. There is moderate evidence that Roux-en-Y gastric bypass performs better compared to sleeve gastrectomy or adjustable gastric banding for metabolic, cardiovascular, and renal function outcomes and for postoperative complications. Finally, no models to predict weight loss have undergone internal or external validation.
Conclusions: Relatively few nonrandomized studies examine the comparative effectiveness and safety of bariatric therapies in the Medicare population. Large gaps remain in regard to comparisons of individual bariatric surgical procedures to each other, and very limited evidence exists in regard to patient-centered outcomes such as quality of life after surgery.