Penicillin allergy is a significant barrier to optimal antibiotic stewardship, contributing to increased antimicrobial resistance, higher treatment costs, prolonged hospital stays and elevated mortality rates. However, approximately 90% of penicillin allergy labels are disproven on evaluation. Risk stratification-based penicillin allergy evaluation (PAE) has proven safe and effective outside allergology departments, yet its adoption in routine clinical practice remains limited. This study aims to examine the implementation of a risk stratification-based PAE programme across hospitals in Western Norway.

We aim to examine implementation of a risk stratification-based programme for evaluating and de-labelling declared penicillin allergy in Western Norway hospitals in a multicentre study. The study employs a combined stepped wedge- and interrupted time series design. It includes hospitals of varying service levels in both urban and rural settings. Each participating centre receives 12 months of active implementation support, followed by a 6 month postintervention evaluation. The study is guided by the Consolidated Framework for Implementation Research and the Expert Recommendations for Implementing Change. Implementation outcomes assessed include acceptability, fidelity, adoption, penetration, feasibility and sustainability.

The study was approved by the Regional Ethics Committee of Western Norway (approval number: 199210). All legal and formal research requirements are met. Results will be published open access in peer-reviewed journals and included in the first author’s publicly available PhD. Nationwide implementation of PAE is planned, informed by the study’s findings.

Current Research Information System (Cristin) in Norway project identification number: 2500736.