Purpose Obesity is associated with increased morbidity and mortality. Weight loss due to gastric bypass (GBP) surgery improves clinical outcomes and may be a cost-effective intervention. To estimate the cost-effectiveness of GBP compared to clinical treatment in severely obese individuals with and without diabetes in the perspective of the Brazilian public health system. Materials and Methods A Markov model was developed to compare costs and outcomes of gastric bypass in an open approach to clinical treatment. Health states were living with diabetes, remission of diabetes, non-fatal and fatal myocardial infarction, and death. We also included the occurrence of complications related to surgery and plastic surgery after the gastric bypass surgery. The direct costs were obtained from primary data collection performed in three public reference centers for obesity treatment. Utility values also derived from this cohort, while transition probabilities came from the international literature. A sensitivity analysis was performed to evaluate uncertainties. The model considered a 10-year time horizon and a 5% discount rate. Results Over 10 years, GBP increased quality-adjusted life years (QALY) and costs compared to clinical treatment, resulting in an incremental cost-effectiveness ratio (ICER) of Int$1820.17/QALY and Int$1937.73/QALY in individuals with and without diabetes, respectively. Sensitivity analysis showed that utility values and direct costs of treatments were the parameters that affected the most the ICERs. ConclusionThe study demonstrated that GBP is a cost-effective intervention for severely obese individuals in the Brazilian public health system perspective, with a better result in individuals with diabetes.

Total costs were higher in the surgical group in the first 2 years after surgery. However, from the third year on, the costs were lower than in the clinical group.

BACKGROUND Obesity is a global health problem that is continuing to increase in the young population. In Brazil, the frequency of obesity in 2018 was 19.8%. Several comorbidities are directly associated with obesity, such as non-alcoholic fatty liver disease (NAFLD), which is considered the most common liver disorder in Western countries and affects up to 46% of adults. Bariatric surgery is effective in treating obesity and can improve NAFLD; however, the effect of bariatric surgery on body composition, phase angle (PA), and improving NAFLD needs to be further studied. AIM To analyze the PA in the postoperative period of bariatric surgery and to correlate it with changes in body composition and liver disease. METHODS This study is a retrospective cohort study of the analysis of the medical records of patients undergoing bariatric surgery in a reference center of a teaching hospital in Porto Alegre over a 2-year period. Patients older than 18 years whose record contained all information relevant to the study were included. The data analyzed were body composition and PA through electrical bioimpedance and NAFLD through liver biopsy in the pre- and postoperative period. The level of significance adopted for the statistical analyses was 5%. RESULTS We evaluated 379 patients with preoperative data. Regarding PA, 169 patients were analyzed, and 33 patients had liver biopsy pre- and postoperatively with NAFLD information. In total, 79.4% were female, with a mean age of 39.1 ± 10.6 years. The average body mass index (BMI) was 45.9 ± 7.5 kg/m². The PA showed a mean of 5.8 ± 0.62° in the preoperative period and a significant reduction in the postoperative period. A postoperative reduction in body composition data (skeletal muscle mass, fat percentage, fat mass, body cell mass, BMI and visceral fat area) was shown as well. Regarding liver disease, all patients presented a reduction in the degrees and stages of liver disease in the postoperative period, and some had no degree of liver disease at all. CONCLUSION PA decreased after bariatric surgery, with a direct correlation with weight loss and changes in body composition. The decrease in PA was not correlated with the improvement in NAFLD.