Association Between Bariatric Surgery and Long-term Health Care Expenditures Among Veterans With Severe Obesity.

Importance: Bariatric surgery has been associated with improvements in health in patients with severe obesity; however, it is unclear whether these health benefits translate into lower health care expenditures.

Objective: To examine 10-year health care expenditures in a large, multisite retrospective cohort study of veterans with severe obesity who did and did not undergo bariatric surgery.

Design, Setting, and Participants: A total of 9954 veterans with severe obesity between January 1, 2000, and September 30, 2011, were identified from veterans affairs (VA) electronic health records. Of those, 2498 veterans who underwent bariatric surgery were allocated to the surgery cohort. Sequential stratification was used to match each patient in the surgery cohort with up to 3 patients who had not undergone bariatric surgery but were of the same sex, race/ethnicity, diabetes status, and VA regional network and were closest in age, body mass index (calculated as weight in kilograms divided by height in meters squared), and comorbidities. A total of 7456 patients were identified and allocated to the nonsurgery (control) cohort. The VA health care expenditures among the surgery and nonsurgery cohorts were estimated using regression models. Data were analyzed from July to August 2018 and in April 2019.

Interventions: The bariatric surgical procedures (n = 2498) included in this study were Roux-en-Y gastric bypass (1842 [73.7%]), sleeve gastrectomy (381 [15.3%]), adjustable gastric banding (249 [10.0%]), and other procedures (26 [1.0%]).

Main Outcomes and Measures: The study measured total, outpatient, inpatient, and outpatient pharmacy expenditures from 3 years before surgery to 10 years after surgery, excluding expenditures associated with the initial bariatric surgical procedure.

Results: Among 9954 veterans with severe obesity, 7387 (74.2%) were men; the mean (SD) age was 52.3 (8.8) years for the surgery cohort and 52.5 (8.7) years for the nonsurgery cohort. Mean total expenditures for the surgery cohort were $5093 (95% CI, $4811-$5391) at 7 to 12 months before surgery, which increased to $7448 (95% CI, $6989-$7936) at 6 months after surgery. Postsurgical expenditures decreased to $6692 (95% CI, $6197-$7226) at 5 years after surgery, followed by a gradual increase to $8495 (95% CI, $7609-$9484) at 10 years after surgery. Total expenditures were higher in the surgery cohort than in the nonsurgery cohort during the 3 years before surgery and in the first 2 years after surgery. The expenditures of the 2 cohorts converged 5 to 10 years after surgery. Outpatient pharmacy expenditures were significantly lower among the surgery cohort in all years of follow-up ($509 lower at 3 years before surgery and $461 lower at 7 to 12 months before surgery), but these cost reductions were offset by higher inpatient and outpatient (nonpharmacy) expenditures.

Conclusions and Relevance: In this cohort study of 9954 predominantly older male veterans with severe obesity, total health care expenditures increased immediately after patients underwent bariatric surgery but converged with those of patients who had not undergone surgery at 10 years after surgery. This finding suggests that the value of bariatric surgery lies primarily in its associations with improvements in health and not in its potential to decrease health care costs.