Time is running out. No excuses to delay implementation of antimicrobial stewardship programmes: impact, sustainability, resilience and efficiency through an interrupted time series analysis (2017-2022).

Introduction: The WHO declared antimicrobial resistance (AMR) a significant concern in 2014, sparking initiatives to ensure responsible antibiotic use. In human medicine, Antimicrobial Stewardship Programmes (ASPs) in hospitals play a pivotal role in combating AMR. Although evidence supports the effectiveness of ASPs in optimizing antimicrobial use, often the lack of resources becomes an excuse to limit their dissemination and use. This paper provides a comprehensive report on a 6-year analysis of an ASP implemented in a healthcare region in north-east Italy.

Methods: A retrospective data collection was conducted to assess the programme's impact on antibiotic consumption expressed as DDDs/100 patient-days, its sustainability over time, resilience during the COVID-19 pandemic and the efficiency of the ASP (relationship between workload and human resources).

Results: A substantial overall reduction in antibiotic consumption (-14%), particularly in fluoroquinolones (-64%) and carbapenems (-68%), was demonstrated, showcasing the programme's impact. Sustainability was confirmed through enduring trends in antibiotic consumption and ecological analysis over time. The ASP demonstrates resilience by maintaining positive trends even amid the challenging COVID-19 pandemic. Efficiency was underscored by an increase in on-site consultations despite consistent human resources until 2021.

Conclusions: This study offers insights into the prolonged success of a resource-efficient ASP, emphasizing the crucial role of long-term commitment in fostering responsible antibiotic use in the context of global health challenges such as AMR.