Ghent University. Faculty of Medicine and Health Sciences
Abstract
Health care is challenged by the emergence of antibiotic resistance and the slow pipeline of new antibiotics, especially against Gram negative multi-resistant bacteria. The most important cause of emergence and spread of antimicrobial resistance has been a massive overuse of antibiotics worldwide across all ecosystems over the past decades, including humans, animals, aquaculture, and agriculture.
Antimicrobial resistance may lead to more difficult to treat infections and may hence be associated with increased patient mortality, longer hospital stays, and increased healthcare costs. Up to 30% of antimicrobial regimens in hospitals are considered inappropriate. An effective approach to improving antimicrobial use in hospitals is an organised antimicrobial stewardship program.
In this thesis we tried to develop and validate quality indicators in order to monitor antimicrobial stewardship programs in a hospital setting. Furthermore we evaluated key components of an antimicrobial stewardship program to optimize antimicrobial prescribing. With a multidisciplinary panel from four European countries we developed 57 structure indicators from which ten indicators were identified as a minimal set of key indicators. A validation survey in eleven European hospitals showed a significant heterogeneity with regard to their scoring for structural components of effective antibiotic stewardship. We concluded that potential structure indicators examined in this study, with focus on the top-ten indicators, could be used for regular assessment of the extent and strength of hospital antimicrobial stewardship programs.
The feasibility and clinical relevance of measuring a process indicator for appropriate iv use of highly bioavailable antimicrobial drugs, allowing early IV to oral switch, was evaluated revealing a substantial heterogeneity of the performance gap. Absence of an iv-to-po switch programme was associated with more inappropriate prescribing. The results of this study indicated that the iv-to-po quality indicator is widely applicable and could be a tool to evaluate compliance with iv-to-po switch guidelines.
Optimizing antibiotic dosing regimens is a core activity within an antimicrobial stewardship program. Extended and continuous infusions with betalactam antibiotics have been suggested as a means of pharmacokinetic and pharmacodynamic optimisation of antimicrobial therapy. A survey was undertaken to investigate the recommendations on extended and continuous infusions of ceftazidime, cefepime, piperacillin–tazobactam, meropenem and vancomycin by the local antibiotic management teams (AMTs) in Belgian acute hospitals. This survey showed that extended and continuous infusions are widely implemented in Belgian hospitals but revealed significant variation in the recommended dosing regimens.
Two interventional studies were performed to optimize antimicrobial prescribing. These focused on appropriate timing of the initiation of an antimicrobial treatment for presumed infections in the emergency ward and on parenteral to oral conversion of fluoroquinolone antibiotics. We showed that the implementation of merely persuasive interventions such as hospital-wide publication of guidelines in the local drug letter and educational interactive sessions towards nurses and physicians only resulted in limited improvement. However, a pro-active intervention by a clinical pharmacist to stimulate parenteral to oral conversion resulted in a significant reduction of the duration of the intravenous treatment, as well as in treatment cost.
Finally we assessed the functioning of a multidisciplinary infectious diseases team (MIT), which is an example of educational outreach intervention. The MIT formulated a daily average of 5 interventions for non-critically ill adult patients in a teaching hospital. Following bedside assessment by junior staff, diagnostic and therapeutic recommendations were communicated by phone and by notes towards prescribers in the electronic patient file resulting in high acceptance rates, in particular for therapeutic recommendations.
In general this thesis provides indicators to the AMT’s to evaluate their antimicrobial stewardship activities. Proactive interventions on an individual patient level are needed to optimize antimicrobial prescribing
