Risk factors for hospital-based surgical site infections

Surgical site infections (SSIs) contribute to morbidity and are costly to the healthcare system. To identify factors associated with SSIs. Case–control study analyzing the Nationwide Readmission Database (NRD). We identified 45,445 SSIs. Infection rates were higher in those who were obese (BMI ≥ 30) (OR: 1.39, 95% CI 1.28–1.51), tobacco users (OR: 1.08, 95% CI 1.02–1.15), diagnosed with diabetes (OR: 1.16, 95% CI 1.10–1.22), with Elixhauser Comorbidity Index ≥ 2 (OR: 1.14, 95% CI 1.09–1.20), admitted to hospital for 4–6 days (OR: 1.35, 95% CI 1.29–1.42), in medium-size hospital (OR: 1.15, 95% CI 1.05–1.26), or large-size hospital (OR: 1.43, 95% CI 1.31–1.56). In contrast, patients who were 60–79 years old (OR: 0.78, 95% CI 0.73–0.84), 80 years or older (OR: 0.66, 95% CI 0.59–0.73), female (OR: 0.95, 95% CI 0.91–0.99), underweight (BMI < 18.5) (OR: 0.14, 95% CI 0.03–0.59), in a non-metropolitan hospital (OR: 0.83, 95% CI 0.75–0.91), self-pay (OR: 0.82, 95% CI 0.74–0.91), or covered by Medicare (OR: 0.86, 95% CI 0.80–0.91) had lower odds. Initial data entry to NRD is susceptible to human error. Patients who are obese, use tobacco, have multiple comorbidities, and have long hospital stays in medium-to-large-size hospitals are at risk of SSIs. Conversely, odds of SSIs are lower in females, age ≥ 60, BMI < 18.5, self-pay or Medicare (versus private insurance), or at smaller hospitals. Understanding factors associated with SSIs may help surgeons anticipate complications.