OBJECTIVES : The objective of the study was to conduct a systematic review and meta-analysis of economic evaluations of cost-effectiveness regarding the bariatric surgery for treatment of moderate to severe obesity.

METHODS : Systematic review of literature and meta-analysis referring to studies on costs and effectiveness of the bariatric surgery with data on outcomes of chronic noncommunicable diseases associated with overweight and obesity (medication, hospitalizations and mortality)

RESULTS : The systematic review gathered 51 studies with costs and effectiveness of bariatric surgery conducted in diverse countries, published between 2005 and 2018. The majority of studies pointed to reduction in direct costs related to comorbidities after bariatric surgery, in comparison to costs for treatment of comorbidities among patients without surgery. The average cost of bariatric surgery was US$ 49,419.63 (±96,707.49; median=12,661.96 and quartiles of 5,414.5-33,679.10). The average cost of treatment for comorbidities among patients without surgery was US$40,342.30 (±37,716.16; median=31,958.46 and quartiles of 4,871.03-69,200.00). The results of the total effectiveness shown wide benefits of the bariatric surgery in all evaluated items (RR 0.571 CI95% 0.482 – 0.660, p<0,001), including the reduction in total expenditure (RR 0.652 CI95% 0.462 – 0.841, p<0,001), reduction of needs of medicines (RR 0.160 CI95% 0.005 – 0.314, p<0,001), decrease of relative risk of hypertension (RR 0.589 CI95% 0.493 – 0.685, p<0,001), decrease of relative risk of diabetes (RR 0.400 CI95% 0.609 – 0.741, p<0,001), cardiovascular diseases (RR 0.578 CI95% 0.349 – 0.807, p<0,001), dyslipidemia (RR 0.721 CI95% 0.562 – 0.881, p<0,001), obesity-related mortality (RR 0.505 CI95% 0.345 – 0.665, p<0,001), obesity-related cancer (RR 0.675 CI95% 0.609 – 0.741, p<0,001) and depression (RR 0.829 CI95% 0.794 – 0.865, p<0,001), compared to conservative or non-surgical treatment.

CONCLUSIONS : The bariatric surgery is cost-saving and cost-effective in reducing obesity-related diseases