Association between social vulnerability and surgical site infection across surgical procedures

OBJECTIVE: To evaluate the association between neighborhood-level social vulnerability and risk of surgical site infection. DESIGN: Retrospective cohort study from January 1, 2019-December 31, 2024. SETTING: Large academic hospital in the Deep South. PARTICIPANTS: Patients undergoing NHSN-defined procedures by CPT coding (coronary artery bypass graft, colon surgery, craniotomy, spinal fusion, hip prosthesis, knee prosthesis, or abdominal hysterectomy) were included. Social vulnerability index (SVI) percentile and themes were defined by the Centers for Disease Control and Prevention criteria and assigned based on residential ZIP code. METHODS: The primary outcome was development of SSI. Cox proportional hazards models stratified by SSI surveillance duration (30 or 90 days) were used to estimate hazard ratios (HRs) and 95% confidence intervals, adjusting for demographic, clinical, and procedural characteristics. RESULTS: Among 40,954 surgeries, 26,067 patients (63.7%) resided in high SVI ZIP codes. The risk of SSI increased across SVI tertiles (low 1.5%, medium 2.2%, high 2.4%). Compared with those in low SVI tertile, SSI risk was higher for patients in the medium-SVI (aHR 1.40, 95% CI 1.03-1.92) and high-SVI tertile (aHR 1.49, 95% CI 1.10-2.01). Higher SVI socioeconomic status was associated with increased SSI risk (aHR 1.33, 95% CI 1.07-1.64) and higher housing and transportation vulnerability was associated with increased deep incisional and organ space SSI. CONCLUSIONS: Higher neighborhood-level SVI was independently associated with increased risk of SSI across a broad surgical population in the South. Incorporating SVI into preoperative risk assessment may allow targeted infection prevention strategies for hospitals to address barriers to care.