Have Recent Modifications of Operating Room Attire Policies Decreased Surgical Site Infections? An American College of Surgeons NSQIP Review of 6,517 Patients

Background After a Department of Health site visit, 2 teaching hospitals imposed strict regulations on operating room attire, including full coverage of ears and facial hair. We hypothesized that this intervention would reduce superficial surgical site infections (SSIs). Study Design We compared NSQIP data from all patients undergoing operations in the 9 months before implementation (n = 3,077) to time-matched data 9 months post-implementation (n = 3,440). Univariate and multivariable analyses were used to examine patient, clinical, and operative factors associated with SSIs. Power analysis was performed using pre-intervention SSI rates. Results Despite a shift toward more clean cases, there were more SSIs post-implementation (33 vs 30 [1%]; p = 0.95). There were no differences in length of stay, complications, or mortality between the 2 time periods. Overall, SSI increased with wound class: 0.6%, 0.9%, 2.3%, and 3.8% in clean, clean-contaminated, contaminated, and infected cases, respectively. Limiting the review to clean or clean-contaminated cases, incisional SSIs increased from 0.7% (20 of 2,754) to 0.8% (24 of 3,115) (p = 0.85). A multivariable analysis showed that implementation of these policies was not associated with decreased SSIs (odds ratio 1.2; 95% CI 0.70 to 1.96; p = 0.56). The largest predictors of SSIs were preoperative infection, operative time >75th percentile, open wounds, and dirty/contaminated wounds. A hypothetical analysis revealed that a sample size of 485,154 patients would be required to demonstrate a 10% SSI reduction among patients with clean or clean-contaminated wounds. Conclusions Implementation of stringent operating room attire policies do not reduce SSI rates. A study to prove this principle further would be impractical to conduct.