IMPORTANCEResults of previous studies are mixed regarding the economic implications of a Roux-en-Y gastric bypass (RYGB).OBJECTIVE To assess the 5-year incremental health care use and expenditures after RYGB.
DESIGN, SETTING, AND PARTICIPANTSThis population-based cohort study conducted in Ontario, Canada, used a difference-in-differences approach to compare health care use and expenditures between patients who underwent a publicly funded RYGB from March 1, 2010, to March 31, 2013, and propensity score-matched control individuals who did not undergo a surgical bariatric procedure. The study period allowed for a minimum 60 months of follow-up because, at that time, the most recent date for which administrative data on health care and expenditures were available was March 31, 2018. Data sources included the Ontario Bariatric Registry linked to several Ontario health administrative databases and the Electronic Medical Record Administrative Data Linked Database. Health care use and expenditures data for 5 years before and 5 years after the index date (procedure date for RYGB group; random date for controls) were analyzed. Data analyses were performed March 12, 2019, to March 10, 2020.INTERVENTION RYGB procedure.
MAIN OUTCOMES AND MEASURESThe primary outcome was total health care expenditures. RESULTS The final propensity score-matched cohorts comprised 1587 individuals in the RYGB group (mean [SD] age, 47 [10.2] years) and 1587 controls (mean [SD] age, 47 [12.2] years); each group had 1228 women (77.4%) and a mean body mass index (calculated as weight in kilograms divided by height in meters squared) of 46. Mean total health care expenditures (2017 Canadian dollars