Weight Loss Surgery for Mild to Moderate Obesity: A Systematic Review and Economic Evaluation

A systematic review and economic evaluation was commissioned to determine the effectiveness and cost-effectiveness of bariatric surgery for mild [class I, body mass index (BMI) 30 to 34.99] or moderate (class II, BMI 35 to 39.99) obesity. We searched 17 electronic resources (to February 2010) and other sources. Studies meeting predefined criteria were identified, data-extracted and assessed for risk of bias using standard methodology. A model was developed to estimate cost-effectiveness. Two RCTs were included. Evidence from both indicated a statistically significant benefit from laparoscopic adjustable banding (LAGB) compared to a non-surgical comparator for weight loss and in obesity-related comorbidity. Both interventions were associated with adverse events. LAGB costs more than non-surgical management. For people with class I or II obesity and type 2 diabetes (T2D), the incremental cost-effectiveness ratio (ICER) at 2 years is A 20,159 pound, reducing to A 4,969 pound at 5 years and A 1,634 pound at 20 years. Resolution of T2D makes the greatest contribution to this reduction. In people with class I obesity, the ICER is A 63,156 pound at 2 years, A 17,158 pound at 5 years, and A 13,701 pound at 20 years. Cost-effectiveness results are particularly sensitive to utility gain from reduction in BMI, factors associated with poorer surgical performance and diabetes health state costs. Bariatric surgery appears to be a clinically effective and cost-effective intervention for people with class I or II obesity who also have T2D but is less likely to be cost-effective for people with class I obesity.