Bariatric surgery decreases prescription drug costs for metabolic syndrome: a Canadian population-based cohort study

Background Obesity is a chronic disease that is significantly linked to metabolic syndrome. Bariatric surgery is considered the most effective treatment for obesity resulting in long-term weight loss and comorbidity resolution. Prior studies have demonstrated the overall cost effectiveness of bariatric surgery; however, there is little data regarding direct pharmaceutical costs. The objective of this population-based study is to compare the cost of dispensed common prescription medications for metabolic syndrome before and after bariatric surgery. Methods All patients that were enrolled in the Center for Metabolic and Bariatric Surgery who underwent gastric bypass or sleeve gastrectomy between 2013 and 2019 in Manitoba were included. Basic demographic information and outpatient prescription dispensation data were obtained from the Manitoba Population Research Data Repository, which is housed at the Manitoba Centre for Health Policy. Specific drug categories that were reviewed for costs 5 years before and after surgery included Antihypertensives, Lipid Lowering Agents, Insulin and Non-insulin Diabetic Drugs. Results One thousand one hundred and eighty four patients were included in this review. Comparing the 5-year pre- and post-surgery, there was a decrease in the overall amount of drug dispensed and the overall cost for all drug categories in the 5 years following surgery. These categories included Antihypertensives ($506,268.8), Lipid Lowering Agents ($173,866.48), Insulin ($549,305.92), and Other Diabetes Drugs ($513,371.1). Additionally, older patients experienced a larger proportion of cost savings compared to younger patients, with the exception of non-insulin diabetic medications which trended to have more cost savings in the 30–49 year old grouping. Conclusion This is the first Canadian study to use accurate dispensing data from a provincial administrative prescription database to capture long-term cost savings for metabolic prescriptions after bariatric surgery. The results are consistent with the existing literature for prescriptions post-bariatric surgery. Future study will include subgroup analysis by patient age, gender, income quintile, and geography.