Extended Antibiotic Use Questioned in Massive Spine Study

A meta-analysis of 11,875 patients across 11 international studies has concluded that post operative anibiotic prophylaxis has no clinical value.

The study from researchers at the University of Colorado Anschutz Medical Campus, titled, “Extended Postoperative Antibiotic Prophylaxis Is Associated with No Clinical Value and Higher Projected Cost Following Adult Spinal Surgery: A Stratified Meta-Analysis and Probability-Based Cost Projections,” was was published in the September 2024 edition of JBJS Reviews.

The team conducted a comprehensive literature search using several online databases: PubMed, MEDLINE via Ovid, Web of Science, Cochrane database, and Science-Direct. Their goal was to determine the value of different protocols for postoperative antibiotic prophylaxis following spinal surgery including:

1. Postoperative antibiotic prophylaxis for (<48 hours) vs. extended postoperative antibiotic prophylaxis (>48 hours)
2. Short course (24 hours) vs. E-PAP (72 hours)

David Ou-Yang, M.D., associate professor at the University of Colorado, explained the genesis of the study to OTW, “Surgical site infections are a major concern following spine surgery, with reported incidence rates ranging from 0.7% to 16.1%.”

“These infections also represent 21.8% of hospital-acquired infections and result in additional management costs ranging from $20,000 to $94,000 per patient. Although the North American Spine Society’s 2013 guidelines for postoperative antibiotic use are based on Grade B evidence, adherence to these recommendations remains suboptimal.”

Mohamed Awad, M.D., M.B.A., research instructor at the University of Colorado, added, “Under the Hospital-Acquired Conditions Reduction Program, the Centers for Medicare & Medicaid Services [CMS] penalizes hospitals with high rates of infections each year by reducing their reimbursements.”

“This penalty, along with an increase in infection rates, has the potential to generate a ‘butterfly effect’, pushing institutions toward extended postoperative antibiotic prophylaxis. The potential for extended postoperative antibiotic prophylaxis to reduce infections and avoid CMS penalties deserves further investigation.”

“Even though short-term antibiotic use is becoming the norm in North America, international practices still favor extended protocols, ultimately contributing to antimicrobial resistance,” explained Nicholas Alfonso, M.D., co-author and assistant professor, University of Colorado, to OTW.

“This discrepancy and conflicting literature led us to address whether the current literature supports extended postoperative antibiotic prophylaxis, to determine the value (outcome and projected cost) of different extended postoperative antibiotic prophylaxis protocols, and to provide the community with an evidence-based conclusion.”

“To address these research questions and attain highly valid data, we followed level 1 sub-group meta-analysis to determine the risk estimates. To translate these risk estimates of our outcomes into projected cost, we also calculated the probability-based projected cost by multiplying risk by reimbursement.”

11,875 Patients, 11 Studies, 6 Different Countries (37% From North America)

“Our meta-analysis consists of 11,875 patients across 11 studies from 6 different countries,” explained Dr. Alfonso to OTW.

“The analyses of all included studies and randomized controlled trials (RCTs) demonstrated that extended postoperative antibiotic prophylaxis protocols have no significant value in reducing the incidence of superficial and deep surgical site infections. Extended postoperative antibiotic prophylaxis protocols were associated with significantly longer hospital stays and higher projected costs compared with short course protocols.”

“Collectively, this amounts to $309.9 and $244.4 per episode excess hospital stay expenditure for extended postoperative antibiotic prophylaxis 48 hours and extended postoperative antibiotic prophylaxis 72 hours, respectively.”

“It is important to note that only 36.6% of these studies were conducted in North America, and among the four North American studies, only one was an RCT. Therefore, our study emphasizes the need for global standardization of antibiotic prophylaxis guidelines by adhering to evidence-based practices to improve patient outcomes and address antimicrobial resistance.”

Dr. Ou-Yang added, “To our knowledge, this is the first study to comprehensively quantify both the lack of clinical value, and the higher costs associated with extended antibiotic use following spine surgery. By stratifying the data and focusing on a probability-based cost projection, we were able to clearly demonstrate that longer prophylaxis does not equate to better outcomes, and in fact, leads to unnecessary expenditure.”