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

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. 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. 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. 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.