Analyzing the Social Vulnerability Index With Metabolic Surgery

The social vulnerability index (SVI) is a census tract-level population-based measure generated from 16 socioeconomic and demographic variables on a scale from 1 (least) to 100 (most) vulnerable. This study has three objectives as follows: 1) to analyze multiple ways of utilizing SVI, 2) compare SVI as a group measure of marginalization to individual markers, and 3) to understand how SVI is associated with choice of surgery in metabolic surgery.

We retrospectively identified adults undergoing Roux-en-Y gastric bypass and gastric sleeve in 2013-2018 National Surgical Quality Improvement Program data from a single academic center. High SVI was defined as >75^th percentile. Low SVI was coded as <75^th percentile in measure 1 and < 25^th percentile in measure 2. Chi-square and Mann-Whitney U tests were utilized for categorical and continuous variables, respectively. Multivariable regression models were performed comparing SVI to marginalized status as a predictor for type of metabolic surgery.

We identified 436 patients undergoing metabolic surgery, with a low overall morbidity (6.1%). Complication and readmission rates were similar across comparator groups. The logistic regression models had similar area under the curve, supporting SVI as a proxy for individual measures of marginalization.

SVI performed as well as marginalized status in predicting preoperative risk. This suggests the validity of using SVI to identify high risk patients. By providing a single, quantitative score encompassing many social determinants of health, SVI is a useful tool in identifying patients facing the greatest health disparities.