Sustaining stewardship: longitudinal evaluation of an integrated antimicrobial programme in the ICU

To evaluate the long-term sustainability and impact of an integrated electronic medical record-driven antimicrobial stewardship (AMS) ward round in an ICU at a tertiary referral hospital. The study assessed antimicrobial prescribing patterns, acceptance of stewardship recommendations, and antimicrobial consumption over 7 years.

A prospective review commenced with implementation of the ICU-AMS ward round at Austin Health in 2017. When AMS recommendations were given, data were collected including patient demographics, antimicrobial prescribing, classification of recommendation, and acceptance. Antimicrobial use was assessed via DDDs per occupied bed day per month and analysed using interrupted time series analysis. Logistic regression examined patient and clinician factors associated with recommendation acceptance.

Over 7 years, 9163 AMS recommendations were made for 4610 patients. Recommendation acceptance was high, with antibiotic escalation the most accepted (95%) and discontinuation least accepted (82%). Recommendations were more likely to be accepted in immunocompromised (OR 1.31, P = 0.003) and non-surgical patients (OR 1.31, P < 0.001). Recommendations provided by AMS physicians who identified as men were more likely to be accepted (OR 1.23, P = 0.003). Antimicrobial consumption trends showed significant decreases in piperacillin/tazobactam, meropenem, ciprofloxacin and vancomycin use post-implementation. Amoxicillin/clavulanate use increased, suggesting potential compensatory prescribing.

This study demonstrates the long-term effectiveness and sustainability of an ICU-AMS programme, achieving high recommendation acceptance and sustained reductions in broad-spectrum antimicrobial use. Continued efforts should focus on optimizing stewardship practices, addressing barriers to acceptance, and evaluating compensatory prescribing patterns.