A population based study of bariatric surgery in Illinois

Background: Utilization of metabolic and bariatric surgery has increased significantly over the last 2 decades, yet barriers to access remain. Objectives: This study aimed to 1) define rates of metabolic and bariatric surgery utilization for qualifying adults in Illinois and 2) describe patient characteristics associated with undergoing surgery at Illinois hospitals with low metabolic and bariatric surgery volume. Setting: Metabolic and bariatric surgery at all nonfederal Illinois hospitals was included. Methods: Illinois hospital administrative data for 2016–2022 metabolic and bariatric surgery procedures (numerators) and Illinois Behavioral Risk Factor Surveillance System population estimates (denominators) were used to compute metabolic and bariatric surgery rates per estimated 100,000 Illinois residents ages 18–69 who qualified for metabolic and bariatric surgery based on National Institutes of Health Guidelines. Zip code median income was obtained from census data. Multivariable logistic regression was used to identify patient characteristics associated with receiving metabolic and bariatric surgery at low volume hospitals (LVHs), defined as less than 50 annual bariatric procedures. Results: The average annual metabolic and bariatric surgery rate was 702 per 100,000 qualifying Illinois adults. Rates were highest among non-Hispanic Black patients (890/100,000) and lowest for Hispanic patients (396/100,000) and patients from zip codes with median household income <$75,000. Lower median household income was the only characteristic associated with use of LVHs. Conclusions: Metabolic and bariatric surgery procedures almost doubled over the study period in Illinois, increasing the most for non-Hispanic Black and Medicaid patients. However, Hispanic and low-income patients still have rates well below the state average.