Impacts of bariatric surgery on costs and health outcomes of patients in Brazil: Interrupted time series analysis of multi-panel data

Study design Original research Obesity is one of the most important public health problems worldwide, presenting significant socioeconomic impacts in health systems. Considering the rising costs of health care and the escalating burden of obesity in diverse countries, there has been increasing trends in examination of cost-effectiveness of health interventions towards prevention and treatment of obesity and its effects on comorbidities. Bariatric surgery has been considered an effective intervention for reducing moderate to severe obesity and improvement of obesity-related morbidities. Methodology Interrupted Time-Series Analysis (ITSA) on costs and health outcomes from retrospective cohort of 114 patients who had bariatric surgery at the Hospital of Clinics from the University of Sao Paulo. Medical records encompassing complete data on anthropometric, hemodynamic and biochemical parameters, utilization of resources and costs for health care procedures and regular assessments of patients’ health status associated with bariatric surgery at individual level were included in the study. Data on utilization of resources during outpatient and inpatient health care were used for estimation of patient’s direct costs referring to bariatric surgery, and 6-month pre- and post-intervention periods, adopting health system perspective in micro-costing approach. Results Mean direct costs of hospitalization (-US$2,762.22; −23.2%), image exams (-US$7.53; −0.8%) and medication (-US$175.37; −25,7%) presented decrease after bariatric surgery, and total direct cost (US$1,375.37; +138%), consultations (US$0.42; +2.4%) and laboratory exams (US$68.96; +63.4%) had increase. Reduction in weight, BMI, LDL, triglycerides, insulin, glucose-linked hemoglobin, and glucose showed improvements in patients’ health status after bariatric surgery. Cholesterol, VLDL, and HDL presenting increase after surgery. Conclusion Bariatric surgery represents an effective intervention for treatment of moderate to severe obesity with extensive benefits regarding health promotion and reduction of burden of disease. Trends in direct costs and multiple health outcomes showed post-intervention improvements in patients’ health status and reduction of health care needs of individuals.