OBJECTIVES: Obesity has high prevalence rates among the Brazilian population. The aim of the present study was to evaluate the health resources utilization during and after surgery and its economic impact on Brazil's SHS sample.

METHODS: Retrospective cohort study using 11 health carriers from Healthtech Orizon billing system, which represents 21% of SHS. Patients selected were aged above 18 years with severe obesity inferred through bariatric surgery (criteria BMI>35 kg/m² with comorbidities or BMI>40 kg/m²) conducted in the SHS between Jan-1st-14 and Dec-31th-17 and followed up over 3 years after the procedure, totaling 32,796 patients. During the study period, all expenditure of patients was analyzed.

RESULTS: Over the 43 months of study, the number of surgeries increased 31% with a median of 758 surgeries per month, being 37% female patients with age between 25-49 years old. Surgery complications rate was 11%, where the revisional bariatric surgery was the most prevalent. There were 34,000 medical appointments with an average of 4 exams per patient in the follow-up period. The median surgery cost was $22,700 BRL and median cost per patient was $29,800 BRL including all resources. Total cost during and up to 3 years after surgery was $1,2 billion BRL, 53% of the amount represents additional expenses other than the bariatric surgery.

CONCLUSION: Results show that the number of bariatric procedures has increased in Brazil from the SHS perspective. Although it is a single event, it requires a wide use of medical resources during and post-intervention. Costs are high and represent the surgery-related expenses and costs related to recovery and patient management within the 3 following years. These findings strengthen the idea that bariatric surgery is not a one-off event in the treatment of obesity, but one-step of a continuous treatment process for this chronic disease.