Operating Room Traffic as a Modifiable Risk Factor for Surgical Site Infection.

BACKGROUND Surgical site infections (SSI) contribute to surgical patients' morbidity and costs. Operating room traffic may be a modifiable risk factor for SSI. We investigated the impact of additional operating room personnel on the risk of superficial SSI (sSSI). PATIENTS AND METHODS In this matched case-control study, cases included patients in whom sSSI developed in clean surgical incisions after elective, daytime operations. Control subjects were matched by age, gender, and procedure. Operating room personnel were classified as (1) surgical scrubbed, (2) surgical non-scrubbed, or (3) anesthesia. We used conditional logistic regression to test the extent to which additional personnel overall and from each work group were associated with infection. RESULTS In total, 474 patients and 803 control subjects were identified. Each additional person among total personnel and personnel from each work group was significantly associated with greater odds of infection (all personnel, odds ratio [OR] = 1.082, 95% confidence interval [CI] 1.031-1.134, p = 0.0013; surgical scrubbed OR = 1.132, 95% CI 1.029-1.245, p = 0.0105; surgical non-scrubbed OR = 1.123, 95% CI 1.008-1.251, p = 0.0357; anesthesia OR = 1.153, 95% CI 1.031-1.290, p = 0.0127). After adjusting for operative duration, body mass index, diabetes mellitus, and vascular disease, additional personnel and sSSI were no longer associated overall or for any work groups (total personnel OR = 1.033, 95% CI 0.974-1.095, p = 0.2746; surgical scrubbed OR = 1.060, 95% CI 0.952-1.179, p = 0.2893; surgical non-scrubbed OR = 1.023 95% CI 0.907-1.154, p = 0.7129; anesthesia OR = 1.051, 95% CI 0.926-1.193, p = 0.4442). CONCLUSION The presence of additional operating room personnel was not independently associated with increased odds of sSSI. Efforts dedicated to sSSI reduction should focus on other modifiable risk factors.