Data Sources

We used the University of Wisconsin Hospital and Clinics (UW) institutional bariatric surgery registry (BSR) to identify our study cohort. The BSR includes all patients who undergo bariatric surgery at UW and contains information on baseline patient demographics, comorbidities and postoperative resolution, and surgical outcomes. A trained data extractor not involved in patient care reviewed all inpatient and outpatient visits, diagnostic studies, and lab values recorded in the UW electronic health record (EHR) to populate the BSR. Additional height and weight data beyond the 1-year follow-up reported in the BSR were extracted from the EHR.

Three geocoded databases were used to analyze social determinant variables at the neighborhood level: (1) ADI for neighborhood socioeconomic deprivation^22,23; (2) rural-urban commuting area (RUCA) database for neighborhood urbanicity²⁴; and (3) walkability index for neighborhood walkability.²⁵

We followed the Strengthening the Reporting of Observational Studies in Epidemiology guidelines within the Enhancing the QUAlity and Transparency Of health Research network in the methodology and reporting of this study.²⁶