Appropriateness of Surgical Antimicrobial Prophylaxis Practices in Australia

IMPORTANCE: Surgical antimicrobial prophylaxis (SAP) is a common indication for antibiotic use in hospitals and is associated with high rates of inappropriateness. OBJECTIVE: To describe the SAP prescribing practices and assess hospital, surgical, and patient factors associated with appropriate SAP prescribing. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, national, quality improvement study with retrospective analysis of data collected from Australian hospitals via Surgical National Antimicrobial Prescribing Survey audits from January 1, 2016, to June 30, 2018. Data were analyzed using multivariable logistic regression. Crude estimates of appropriateness were adjusted for factors included in the model by calculating estimated marginal means and presented as adjusted-appropriateness with 95% confidence intervals. MAIN OUTCOMES AND MEASURES: Adjusted appropriateness and factors associated with inappropriate prescriptions. RESULTS: A total of 9351 surgical episodes and 15 395 prescriptions (10 740 procedural and 4655 postprocedural) were analyzed. Crude appropriateness of total prescriptions was 48.7% (7492 prescriptions). The adjusted appropriateness of each surgical procedure group was low for procedural SAP, ranging from 33.7% (95% CI, 26.3%-41.2%) for dentoalveolar surgery to 68.9% (95% CI, 63.2%-74.5%) for neurosurgery. The adjusted appropriateness of postprocedural prescriptions was also low, ranging from 21.5% (95% CI, 13.4%-29.7%) for breast surgery to 58.7% (95% CI, 47.9%-69.4%) for ophthalmological procedures. The most common reason for inappropriate procedural SAP was incorrect timing (44.9%), while duration greater than 24 hours was the most common reason for inappropriate postprocedural SAP (54.3%). CONCLUSIONS AND RELEVANCE: High rates of inappropriate procedural and postprocedural antimicrobial use were demonstrated across all surgical specialties. Reasons for inappropriateness, such as timing and duration, varied according to the type of SAP and surgical specialty. These findings highlight the need for improvement in SAP prescribing and suggest potential targeted areas for action.