Delivering Outpatient Parenteral Antimicrobial Therapy (OPAT) in a Changing National Health Service (NHS): Benefits, Risks, Challenges, and Future Prospects

This thesis presents a comprehensive investigation into the practice of administering intravenous antimicrobials outside inpatient settings—known as Outpatient Parenteral Antimicrobial Therapy (OPAT)—within the UK National Health Service (NHS) context. Drawing on ten published studies employing diverse methodologies, in which I served as the lead author and primary contributor, this body of work critically examines OPAT's benefits, risks, challenges, and innovations, with the overarching aim of providing evidence-based approaches for optimising service delivery.

The studies explore multiple facets of OPAT practice. A retrospective evaluation of a decade of service delivery in Sheffield demonstrated its clinical efficacy, cost-effectiveness, and patient acceptability. A cost-consequence analysis indicated that OPAT incurred approximately 39% of national average cost for equivalent inpatient care. Additional studies assessed health-related quality-of-life among OPAT recipients in Derby and identified predictors of outcomes in complex infections, such as infective endocarditis and necrotising otitis externa. Two studies reported the development and validation of a risk prediction model for unplanned hospitalisation, offering a pragmatic tool for improving patient selection.

Safety-related concerns were further addressed through a systematic review and meta-analysis on venous thromboembolism, which revealed low rates of non-catheter-related (0.2%) and catheter-related (1.1%) thrombosis in the OPAT setting, thereby informing future thromboprophylaxis recommendations. A national cross-sectional survey identified significant variation in OPAT practices and service provision, highlighting systemic challenges and opportunities for standardisation. Finally, two recent studies examined innovative approaches—telemedicine-supported OPAT and elastomeric infusion devices—demonstrating their potential to enhance accessibility and efficiency, particularly in underserved populations.

Collectively, the studies provide robust evidence that OPAT is a safe, clinically effective, and cost-efficient use of NHS resources. However, its full potential remains constrained by inconsistent implementation and geographical variation. Realising OPAT’s full benefits will require a coordinated national approach encompassing innovative delivery methods, a standardised funding framework, and comprehensive commissioning policies.