Bariatric surgery has emerged as an effective approach to reducing body weight and improving obesity-related complications, especially for patients living with diabetes. The surgery has been shown to significantly reduce weight over time. Recent research also indicates that bariatric surgery may provide benefits to people with diabetes in addition to sustained weight loss. Among severely obese patients with diabetes, bariatric surgery has been associated with aiding in reductions in A1C, allowing many patients to stop taking diabetes medications.

Data suggest that bariatric surgery is a successful long-term treatment of obesity for people with diabetes, but it’s important to remember that these procedures are expensive. Studies have shown that the average cost of bariatric surgery exceeds $13,000, and that doesn’t include additional costs that may ensue in the months following surgery. Consequently, evidence on the cost-effectiveness of bariatric surgery is needed.

A New Cost-Effective Analysis

In the September 2010 issue of Diabetes Care, my colleagues and I conducted a study to estimate the cost-effectiveness of bariatric surgery among severely obese patients with diabetes. We wanted to assess whether bariatric surgery reduces A1C and other risk factors enough to lower diabetes complications and improve quality of life. We estimated costs, quality-adjusted life-years (QALYs), and cost-effectiveness of bariatric surgeries relative to usual diabetes care for severely obese individuals who were newly diagnosed with diabetes and for those with established diabetes.

“Gastric bypass and gastric banding were cost-effective methods of reducing mortality and diabetes complications in severely obese adults with diabetes.”

In all of our analyses, bariatric surgery increased QALYs and increased costs. Gastric bypass surgery had cost-effectiveness ratios of $7,000 per QALY for severely obese patients with newly diagnosed diabetes and $12,000 per QALY for severely obese patients with established diabetes. Gastric banding surgery had cost-effectiveness ratios of $11,000 per QALY and $13,000 per QALY for the respective groups. We concluded that gastric bypass and gastric banding were cost-effective methods of reducing mortality and diabetes complications in severely obese adults with diabetes.

Assessing the Clinical Implications

According to guidelines from the NIH, patients with a BMI of 40 kg/m2 or higher or a BMI between 35 kg/m2 and 40 kg/m2 plus a comorbidity like diabetes may be candidates for bariatric surgery. In our sensitivity analysis for people with a BMI between 30 kg/m2 and 34 kg/m2, we estimated higher cost-effectiveness ratios than those for more obese patients, but the ratios are still reasonably attractive. More data on bariatric surgery in this BMI range are needed to confirm these results. More research is also needed on the types of bariatric surgery and their efficacy in diabetic populations. There are currently few direct trials comparing gastric bypass and gastric banding procedures. A randomized trial comparing bypass and banding would hopefully provide more compelling evidence on the relative cost-effectiveness of the two procedures.

Despite the limitations in our study in Diabetes Care, the findings do show that gastric bypass and gastric banding surgery appear to provide cost-effective methods of reducing mortality and diabetes complications. Healthcare costs should be expected to increase if more people receive bariatric surgery, but these increased costs appear to offer good value. As more trials directly compare bypass and banding surgery and more studies examine the long-term effects of bariatric surgery, the hope is that estimates of the cost-effectiveness of these procedures will become more fine tuned and help enhance policy decisions.

References

Hoerger TJ, Zhang P, Segel JE, Kahn HS, Barker LE, Couper S. Cost-effectiveness of bariatric surgery for severely obese adults with diabetes. Diabetes Care. 2010;33:1933-1939. Available at:http://care.diabetesjournals.org/content/33/9/1933.full.

Buchwald H, Estok R, Fahrbach K, et al. Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis. Am J Med. 2009;122:248-256.

Keating CL, Dixon JB, Moodie ML, et al. Cost-effectiveness of surgically induced weight loss for the management of type 2 diabetes: modeled lifetime analysis. Diabetes Care. 2009;32:567-574.

Ikramuddin S, Klingman D, Swan T, Minshall ME. Cost-effectiveness of Roux-en-Y gastric bypass in type 2 diabetes patients. Am J Manag Care. 2009;15:607-615.