ORCID

Abstract

BackgroundPenicillin allergy records are common; 15% of hospital inpatients report a penicillin allergy record, but the majority, estimated to be >95%, can take penicillin after formal testing. Penicillin allergy records are associated with several patient, healthcare-system and wider societal harms thought to be due to the avoidance of non-penicillin antibiotics, which are often first line for common infections. Testing patients with penicillin allergy records and removing them if they test negative is called penicillin allergy de-labelling and is traditionally the role of allergists. More recently, non-allergy healthcare workers have been shown to be able to safely remove low risk penicillin allergy records, which enables more patients to receive first line antibiotic therapy. However, it is likely that multiple barriers still exist because penicillin allergy de-labelling is not yet standard of care for inpatients with infections.AimTo design and develop a complex intervention that enables non-allergy healthcare workers to remove incorrect penicillin allergy records for hospital inpatients, to optimise antimicrobial therapy.MethodsTo determine the safety, efficacy and key components of non-allergist delivered penicillin allergy de-labelling interventions in clinical settings, a systematic review of the literature investigated several databases from inception to January 2021, to look at which healthcare workers were delivering penicillin allergy de-labelling and in which healthcare settings. The efficacy and the safety of penicillin allergy de-labelling, grouped by the de-label methods used, was synthesised. The intervention components of the penicillin allergy de-labelling interventions were catalogued as per the Effective Practice and Organisation of Care taxonomy of health systems interventions. The systematic review, which included 69 publications, identified a penicillin allergy de-labelling toolkit, which along with the findings of common components of penicillin allergy de-labelling interventions (guidelines, education and a testing protocol), was used to develop a feasibility penicillin allergy de-labelling intervention. This was then delivered over three months by a care team of doctors and pharmacists. The patients offered penicillin allergy de-labelling as part of the feasibility study were invited to be interviewed to explore their views on being offered inpatient penicillin allergy de-labelling and doctors, nurses and pharmacists were interviewed to explore their views of the penicillin allergy de-labelling patient pathway and to explore their role in that pathway. The interview transcripts were analysed using Reflexive Thematic Analysis. The Person Based Approach was used to develop the penicillin allergy de-labelling (PADL) complex intervention. Patient and healthcare worker barriers and enablers to implementation of the proposed PADL pathway were explored, before undertaking a behavioural analysis to identify key intervention design objectives and identify the key features of the implementation intervention required to achieve each objective to be developed. A logic model, integrating the Theoretical Domains Framework (TDF) to identify the behavioural influences on PADL and the Behaviour Change Wheel (BCW) to show how the implementation intervention is hypothesized to address the target behaviours was then developed and reviewed by stakeholders and topic experts for further refinement and optimisation. The implementation components were developed and a proposed outline was produced to describe how the implementation intervention would be evaluated. Finally, the penicillin allergy de-labelling implementation intervention was tested in a single hospital and evaluated using mixed methods using the Consolidated Framework of Implementation Research and Reach Adoption implementation Maintenance Qualitative Evaluation for Systematic Translation.FindingsThe systematic review identified 69 eligible studies which reported on the successful de-label of 5019 patients (4314 adults and 461 children) and showed that non-allergist delivered penicillin allergy de-labelling was effective and safe, predominantly delivered by doctors or pharmacists in the inpatient setting. Penicillin allergy de-labelling was successfully delivered in the study hospital by a small team of doctors and pharmacists; it was safe and enabled patients to be switched to first line therapy post de-label. The qualitative studies with patients found those who were successfully de-labelled were positive about the experience and those who declined testing did so for a variety of reasons but highlighted the importance of good communication about the risks and benefits of testing. The penicillin allergy de-labelling pathway was acceptable to healthcare workers and aligned with their roles and current healthcare processes but competing priorities were a significant barrier. The implementation intervention included several components designed to facilitate inpatient penicillin allergy de-labelling and was successfully delivered in the hospital. Data on 497 risk assessed patients are presented of which 186 (37.4%) patients were de-labelled, and the rate of antibiotic associated harm low, 4 (2.3%).ConclusionThe penicillin allergy de-labelling implementation intervention successfully increased non-specialist workforce penicillin allergy de-labelling of low-risk patients. The penicillin allergy de-labelling implementation intervention will take time to establish itself as standard of care and so ongoing leadership and championing are needed to further embed penicillin allergy de-labelling.Contents

Awarding Institution(s)

University of Plymouth

Supervisor

Mathew Upton, Bridie Kent, Jonathan Sandoe, Sarah Tonkin-Crine

Document Type

Thesis

Publication Date

2026

Embargo Period

2026-07-21

Deposit Date

July 2026

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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