Although bariatric surgery is the most effective obesity treatment, few nationwide cohort studies have evaluated its safety. This study aimed to evaluate surgical trends after insurance coverage implementation and analyze the surgical outcomes of bariatric surgery.

A retrospective analysis of bariatric surgery in patients with obesity was conducted using data from Korean National Health Insurance System (NHIS) claims. We evaluated short-term outcomes.

We enrolled 7,360 patients who underwent bariatric surgery for obesity between January 2019 and December 2021 in this study. Before the introduction of insurance coverage, approximately 500 bariatric surgeries were performed annually, which increased to around 2,000 procedures per year following the implementation of coverage. There were 5,139 sleeve gastrectomies (69.8%), 927 Roux-en-Y gastric bypasses (12.6%), 375 biliopancreatic diversions with duodenal switch (5.1%), and 895 gastric banding–related surgeries (12.2%), including revision surgeries. The mean postoperative hospital stay was 5.9 days, and patients with higher body mass indexes (≥ 50 kg/m2) experienced longer hospital stays (8.0 ± 6.4 days, p < 0.001). Major complications and mortality rates within 30 days postoperatively were 2.6% and 0.01%, respectively. The readmission rate within 30 days postoperatively was 5.5%, and the rate of major complications after readmission was 2.8% during the entire period.

The NHIS’s coverage of bariatric surgery in 2019 led to greater numbers of bariatric procedures performed in South Korea, with acceptable surgical outcomes concerning complication rates and hospital stay durations. These findings highlight the positive impact of national insurance coverage on the accessibility and safety of bariatric surgery in South Korea.