Outcomes are Local: Patient, Disease, and Procedure-Specific Risk Factors for Colorectal Surgical Site Infections from a Single Institution

Background: Colorectal surgical site infections (SSIs) contribute to postoperative morbidity, mortality, and resource utilization. Risk factors associated with colorectal SSI are well-documented. However, quality improvement efforts are informed by national data, which may not identify institution-specific risk factors. Method: Retrospective cohort study of colorectal surgery patients uses institutional ACS-NSQIP data from 2006 through 2014. ACS-NSQIP data were enhanced with additional variables from medical records. Multivariable logistic regression identified factors associated with SSI development. Results: Of 2376 patients, 213 (9.0%) developed at least one SSI (superficial 4.8%, deep 1.1%, organ space 3.5%). Age < 40, BMI > 30, ASA3+, steroid use, smoking, diabetes, pre-operative sepsis, higher wound class, elevated WBC or serum glutamic-oxalocetic transaminase, low hematocrit or albumin, Crohn’s disease, and prolonged incision-to-closure time were associated with increased SSI rate (all P < 0.01). After adjustment, BMI > 30, steroids, diabetes, and wound contamination were associated with SSI. Patients with Crohn’s had greater odds of SSI than other indications. Conclusion: Institutional modeling of SSI suggests that many previously suggested risk factors established on a national level do not contribute to SSIs at our institution. Identification of institution-specific predictors of SSI, rather than relying upon conclusions derived from external data, is a critical endeavor in facilitating quality improvement and maximizing value of quality investments.