The effectiveness of Intravenous (IV) to Oral (PO) Antibiotic Switch (IVOS) interventions in managing community- and hospital-acquired pneumonia - a systematic review

Background: Prolonged intravenous (IV) antibiotic therapy in hospitalised patients with pneumonia increases healthcare costs and hospital length of stay compared to oral (PO) therapy. Antimicrobial stewardship (AMS) interventions promoting timely IV-to-PO antibiotic conversion may reduce healthcare burden without compromising patient outcomes. Optimal design and implementation of such interventions in different healthcare settings, including respiratory medicine remain unclear. Objectives: To evaluate the effectiveness of interventions designed to improve IV-to-PO antibiotic switching practices in managing community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). Methods: The review was registered with PROSPERO (CRD420251039180). PubMed, Scopus, Web of Science, The Cochrane Library databases were searched for studies published from 1995 to 2024 focusing on CAP and/or HAP management or antimicrobials indicated for respiratory infections. Two reviewers independently screened studies using a priori inclusion/exclusion criteria. Study quality was assessed using the Mixed Methods Appraisal Tool. Data was analysed using narrative synthesis. Clinical outcomes (cure rates, mortality, length of stay), economic outcomes (cost savings), and process measures (switching rates, IV antibiotic duration) were examined. Results: 58 studies were included. Interventions included clinical guideline/protocol implementation (n=40), pharmacist-led interventions (n=21), educational programmes (n=7), computerised decision support systems (n=5), audit/feedback systems (n=3), and multidisciplinary team approaches (n=1). Most studies demonstrated 1–4-day reductions in IV antibiotic duration, 1-2 day reductions in hospital length of stay, and cost savings, while maintaining equivalent clinical outcomes. Multimodal approaches outperformed single interventions. Conclusion: Existing AMS interventions effectively promote IV-to-PO switching in CAP/HAP management. Healthcare systems should consider more than one intervention to optimise IV-to-PO antibiotic switch.