Cost-effectiveness of bariatric surgery for severely obese adults with diabetes

Objective: To analyze the cost-effectiveness of bariatric surgery in severely obese adults who have diabetes. Base case: Patients with body mass index (BMI) ≥ 35 who have diabetes. Methods: The Centre for Disease Control (CDC)-RTI Diabetes Cost-Effectiveness Model, which is a Markov simulation model of disease progression and cost-effectiveness for type 2 diabetes, was expanded to consider the effects of bariatric surgery. Interventions considered: Gastric bypass and gastric banding compared with usual diabetes care. Outcomes considered: Diabetes-related and surgical complications, diabetes remission and relapse rates, deaths, costs and quality of life. Results: Bariatric surgery increased quality-adjusted life years (QALYs) and increased costs. Bypass surgery had cost-effectiveness ratios of $7 000 per QALY and $12 000 per QALY for severely obese patients with newly diagnosed and established diabetes, respectively. Gastric banding had cost-effectiveness ratios of $11 000 per QALY and $13 000 per QALY, respectively. In sensitivity analyses, the cost-effectiveness ratios were most affected by assumptions about the direct gain in quality of life and by BMI reduction following surgery. Conclusion: The analysis indicates that gastric bypass and gastric banding are cost-effective methods of reducing mortality and diabetes-related complications in severely obese adults with diabetes.