Effectiveness and implementation of point-of-care procalcitonin embedded in a multifaceted implementation strategy to reduce antibiotic prescription in Swiss primary care: the ImpPro hybrid trial

The development of antimicrobial resistance is associated with antibiotic prescription, which occurs mainly in the outpatient sector. In Swiss primary care, almost half of antibiotics are prescribed for acute respiratory infections. While various antimicrobial stewardship interventions have been shown effective to reduce antibiotic prescription in primary care, their implementation remains a challenge. Among such interventions, a recent study showed a large decrease in antibiotics for lower respiratory tract infections with the use of point-of-care procalcitonin test (POC-PCT) in Swiss primary care. There is a critical need to demonstrate how such an innovation can be adopted and implemented in Swiss primary care practices, and how it ultimately reduces antibiotic prescription.

The overarching aim of this study is to develop a tailored, multifaceted implementation strategy of POC-PCT, embedded in general antibiotic stewardship activities, and to evaluate the implementation of POC-PCT and its effectiveness in reducing antibiotic prescribing in Swiss primary care practices.

The ImpPro study is a hybrid type II effectiveness-implementation trial. It is a cluster-randomized trial with quality circles as the unit of randomisation.

The primary objective of the “effectiveness part” of the study is to assess the effectiveness of POC-PCT implemented via QC to reduce prescriptions of antibiotics commonly used for treatment of LRTI between November and April, by comparing antibiotic reimbursement claims between physicians of intervention and control groups.

The primary objective of the “implementation part” of the study is to evaluate the penetration of POC-PCT (i.e. the percentage of primary care physicians who did rent/buy a POC-PCT device and use it). Secondary objectives are to evaluate acceptability and appropriateness of the POC-PCT and the applied implementation strategies, as well as fidelity and sustainment to and of the POC-PCT and the implementation strategies.

For the implementation part of the study, we will use a mixed-methods approach, including collection and analysis of qualitative data from interviews and focus groups, and quantitative data from surveys. Two of the theoretical theories, models and framework guiding our study are the Consolidated Framework for Implementation Research (CFIR) by Damschroeder et al., and the Implementation Outcome framework by Proctor et al..