Application of new indicators to assess the quality of antimicrobial use in intensive care units

This study explored the feasibility of a bundle of indicators aimed at assessing the quality of antimicrobial use in intensive care units (ICUs) through an observational prospective study spanning 12 quarters (January 2019-December 2021) in a 1290-bed teaching hospital in Spain. Members of the antimicrobial stewardship programme team selected the indicators to analyse the quality of antimicrobial use based on consumption data from a list proposed in a previous study. Antimicrobial use in the ICU was measured as defined daily dose (DDD) per 100 occupied bed-days. Trends and points of change were analysed with segmented regression. The intravenous macrolides/intravenous respiratory fluoroquinolones ratio in the ICU increased progressively, although not significantly, by 11.14% per quarter, likely related to prioritization of the use of macrolides in serious community-acquired pneumonia and the coronavirus disease 2019 pandemic. A remarkable upward trend of 2.5% per quarter was detected in the anti-methicillin-susceptible Staphylococcus aureus/anti-methicillin-resistant S. aureus agents ratio in the ICU, which could be explained by the low prevalence of methicillin-resistant S. aureus at the study centre. Patterns of amoxicillin-clavulanic acid/piperacillin-tazobactam ratio and diversification of anti-pseudomonal beta-lactams showed an increment in use over the study. The use of these novel indicators provides additional information for the current analysis of DDD. Implementation is feasible, and led to the detection of patterns that agree with local guidelines and cumulative antibiogram reports, and foster targeted improvement actions within antimicrobial stewardship programmes.