The Role of Guideline-adherent Perioperative Antibiotic Administration and the Risk of Surgical Site Infections After Non-cardiac Surgery: a Report From the Multicenter Perioperative Outcomes Group

Introduction:

Prevention of surgical site infection (SSI) continues to be a major challenge for the health care system since it incurs a substantial toll on public health and significantly inflates health care costs. SSIs are now the leading cause of health care related infections, complicating about 2-5 % of all surgeries(1-3). SSIs affects about 125,000 cases annually accounting for nearly a million excess hospital days and just under $1.6 billion in additional health care costs(4). It is estimated that half of the SSIs are preventable(5) and not surprisingly, the prevention of health care-associated infections has been a priority objective of the U.S. Department of Health and Human Services (HHS)(6) over the past several years. Public reporting of SSI outcomes is now mandatory and reimbursement for management of SSIs is being reduced or denied(7,8) in an effort to curb its incidence.

Despite the institution of stringent measures and surveillance programs, surgical registries continue to show SSI rates of about 2-5%(9,10) and SSIs remain a key cause of prolonged hospitalization, morbidity and death. The continued health care burden caused by SSI calls for closer scrutiny of the current clinical practices especially pertaining to perioperative antibiotic coverage. Although the institution of timely perioperative antibiotic prophylaxis is now a National Quality Anesthesia Care Measure(11), much remains to be known about antibiotic redosing, weight based adjustments and completion of antibiotic infusion prior to skin incision(7).

This study will seek to describe current practice of perioperative antibiotic prophylaxis among MPOG institutions, and in the subset of MPOG centers contributing NSQIP data, to identify the effect of appropriate guideline-based perioperative antimicrobial coverage - specifically regarding selection, timing, weight-based dose adjustments, and redosing - on SSI. The applicable guidelines against which adherence will be assessed are those of the Infectious Disease Society of American (IDSA). To understand the effects of IDSA guideline adherence, the investigators propose to utilize the American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) data collection methodology, and to integrate these prospectively collected outcome data from 6 centers within MPOG with intraoperative anesthesia electronic health record (EHR) data available within MPOG. Beyond the descriptive aim to describe current practice, our primary inferential hypothesis is that adherence to IDSA guidelines regarding appropriate antibiotic selection, timely antibiotic redosing, weight based dose adjustments, and appropriate timing of infusions to ensure completion of administration prior to skin incision will be associated with a lower incidence of SSIs when considered both individually and as a basket of practices, while controlling for common confounders available within the MPOG and NSQIP datasets.

Methods Approval has been obtained from the Yale IRB for this multicenter, observational retrospective study. Data have previously been collected under an umbrella IRB protocol within the University of Michigan. The ACS-NSQIP methodology has been described in detail elsewhere(12). For the NSQIP/MPOG portion of the study, data collected from 01/01/2011 to 07/04/2018 will be extracted. Since the IDSA guidelines were proposed in 02/2013, for the descriptive portion of the study looking at predictors of guideline adherence, data from 01/01/2014 to 07/04/2018 will be extracted from the MPOG database.