The efficacy of multifaceted versus single anesthesia work area infection control measures and the importance of surgical site infection follow-up duration

Background: Earlier a randomized trial showed efficacy of a multifaceted intervention approach for reducing surgical site infection: hand hygiene, vascular care, environmental cleaning, patient decolonization (nasal povidone iodine, chlorhexidine wipes), with feedback on pathogen transmission. The follow-up prospective observational study showed effectiveness when applied to all operating rooms of an inpatient surgical suite. In practice, many organizations will at baseline not be using conditions equivalent to the control groups but instead functionally have had ongoing a single intervention for infection control (e.g., encouraging better hand hygiene). Organizations also differ in how well and long they survey every surgical patient for postoperative surgical site infection. Thus, estimation of the expected net cost savings from implementing multifaceted intervention depends on the relative efficacy of multifaceted approach versus single intervention approaches and on the incidence of surgical site infection, the latter depending itself on the monitoring period for infection development. Methods: The retrospective cohort analysis included 4865 patients from two single intervention and two multifaceted studies, each of the four studies with matched control groups. We used Poisson regression with robust variance to estimate the relative risk reduction in surgical site infections for the multifaceted approach versus single interventions and, with 30-day follow-up versus >= 60-day follow-up for infection. Results: The multifaceted approach was associated with an estimated 68% reduction in postoperative surgical site infections relative to single interventions (risk ratio 0.32, 97.5% confidence interval 0.15-0.70, P = 0.001). There were approximately 2.61-fold more surgical site infections detected with follow-up for at least 60 days of medical records relative to 30 days of records reviewed (97.5% CI 1.62 to 4.21, P < 0.001). Conclusions: An evidence-based, multifaceted approach to anesthesia work area infection control can generate substantial reductions in surgical site infections. A follow-up period of at least 60-days is indicated for infection detection.