Opportunities to measure and improve antimicrobial stewardship in the Irish hospital setting

Background: Antimicrobial resistance (AMR) is one of the most significant threats to public health and increasing levels of resistance among gram negative organisms, and levels of vancomycin-resistant Enterococcus faecium (VRE) are of concern across Europe and in Ireland. Antimicrobial stewardship (AMS) programmes are well established in the Irish hospital setting but it is important that they continue to respond and evolve to the threat of AMR. This can be achieved by investigating new interventions and adopting new diagnostics methods to support hospital AMS programmes and other opportunities to measure and improve AMS programmes. Aim: The overall aim of this research thesis was to investigate opportunities to measure and improve the delivery of AMS programmes in the Irish hospital setting. Methods: A randomised feasibility study was conducted to investigate the implementation of Procalcitonin (PCT) testing in patients with a respiratory tract infection (RTI) as an intervention to support the AMS programme in an Irish hospital setting. An in-depth qualitative process evaluation (PE) of the PCT intervention was conducted to examine the implementation process and to determine the barriers and facilitators to the implementation of PCT as an AMS intervention. The Consolidated Framework for Implementation Research (CFIR) was used to guide data collection, analysis, and interpretation. A systematic review of quality indicators (QIs) for hospital AMS programmes was undertaken, with a critical appraisal of their methodological qualities using the Appraisal of Indicators through Research and Evaluation (AIRE) instrument. A time series analysis (TSA) of antimicrobial consumption (AC) data and AMR data was conducted to investigate trends, and possible relationships between AC and AMR. Results: The feasibility study determined that the introduction of PCT testing in patients with a RTI had a positive impact on antimicrobial prescribing resulting in a significant decrease in duration of antimicrobial prescriptions and decreased length of hospital stay. The qualitative PE identified positive elements of the implementation process along with modifications to improve the delivery of the intervention. The contextual factors which can act as barriers and facilitators to the implementation of AMS interventions were identified and included the concepts of fear, risk and the influence of respiratory clinicians on AMS interventions. The systematic review collated an extensive range of QIs for AMS programmes in the hospital setting which predominantly consisted of process (e.g. infection diagnosis) and structural indicators (e.g. AMS governance), with few outcome indicators developed, a major deficiency in this area. There was limited reporting of information about validation and piloting of QIs sets in practice which is an essential element of the QI development process. The TSA analysis of AC and AMR rates found decreasing or relatively stable rates of AMR in Enterobacterales and VRE isolates but increasing incidence of carbapenem resistance which must be addressed as part of the local AMS programme. Conclusion: This thesis presents a comprehensive and detailed body of research investigating AMS opportunities in the Irish hospital setting. The results of this research indicate that AMS programmes will need to continue to evolve, and dedicated resources will be required to support research in AMS practice. This will include optimising the use of new diagnostic tools such as PCT to support physicians in making antimicrobial prescribing decisions; the incorporation of QIs to assess and improve AMS programmes; and the implementation of in-depth surveillance analysis of AC and AMR using TSA. These measures have the potential to make substantial contributions to hospital AMS measures locally and internationally