Study Finds No Significant Association between Timing of Surgical Antibiotic Prophylaxis and Risk of Surgical Site Infection
Preventing surgical site infection (SSI) is a national priority and a major focus of the Centers for Medicare and Medicaid Services Surgical Care Improvement Project (SCIP), which implemented timing standards for appropriate antibiotic prophylaxis in an effort to reduce SSI. The SCIP measure assesses compliance for prophylactic antibiotic administration within 60 minutes prior to surgical incision. While prophylactic antibiotic timing is a nationally mandated quality metric used for public reporting and performance pay initiatives, it is based on limited evidence to support the effectiveness of reducing SSI. This retrospective cohort study sought to determine whether prophylactic antibiotic timing is associated with decreased SSI. Using national VA SCIP data from 112 VA hospitals, investigators assessed the association of the time in minutes between prophylactic antibiotic administration and surgical incision with subsequent SSI for Veterans who underwent hip or knee arthroplasty, colorectal surgical procedures, arterial vascular surgical procedures, or hysterectomy from 2005 to 2009. Findings also were adjusted for patient, procedure, and outcome variables.
- Of the 32,459 surgical procedures performed at VA hospitals included in this study, prophylactic antibiotics were administered at a median of 28 minutes prior to surgical incision; 92% of patients received antibiotics within the recommended time window. Of all patients, 1,497 (5%) Veterans developed an SSI within 30 days of surgery.
- In adjusted models, no significant association between prophylactic antibiotic timing and SSI was observed. However, there was a significant association between choice of antibiotic and SSI for orthopedic and colorectal procedures:vancomycin hydrochloride was associated with higher SSI occurrence for orthopedic procedures, while cefazolin or quinolone in combination with an anaerobic agent were associated with fewer SSI events for colorectal procedures.
- While adherence to the timely prophylactic antibiotic measure is not bad care, there is little evidence to suggest that it is better care.
- The study sample primarily comprised older male Veterans, and investigators were unable to assess cardiac procedures.
- Intraoperative redosing of antibiotics has been shown to be important for longer procedures, but investigators were unable to assess whether redosing occurred.
NOTE: While currently not feasible using administrative records, authors suggest VA consider monitoring culture data from SSI and update recommendations on the most effective prophylactic antibiotics.
This study was funded by HSR&D (PPO 10-296), and Dr. Richman was supported by an HSR&D Career Development Award. Drs. Hawn and Richman and Ms. Vick are part of HSR&D's Center for Surgical, Medical Acute care Research and Transitions (C-SMART), located in Birmingham, AL.
Hawn M, Richman J, Vick C, et al. Timing of Surgical Antibiotic Prophylaxis and the Risk of Surgical Site Infection. JAMA Surgery March 20, 2013;e-pub ahead of print.