Assessing a penicillin allergy de-labelling implementation intervention in a UK hospital: a process evaluation reporting healthcare workers' experiences.

Background and objectives: Penicillin allergy (penA) records prevent first-line penicillin antibiotic use, but more than 90% are incorrect after formal testing and can be removed ('de-labelled'). We developed an implementation intervention package that supports a multi-professional non-allergy workforce to deliver penicillin allergy de-labelling (PADL) in a UK hospital. To explore the experiences of doctors, nurses, pharmacists and medicines optimization pharmacy technicians (MOPTs) of the implementation intervention package. Methods: Process evaluation utilizing semi-structured interviews with doctors, nurses, pharmacists and MOPTs with a target sample size of 20. Inductive reflexive thematic analysis was used to analyse the data. Results: Fifteen interviews were conducted between 7 November 2024 and 25 March 2025 with six doctors, five pharmacists and four MOPTs. PADL aligned well with the medicine's reconciliation process, the process of accurately listing a person's current medicines, which meant it better aligned with pharmacists' and MOPTs' roles than doctors' roles. Healthcare worker (HCW) confidence to deliver PADL remained low among some doctors and pharmacists, but all reported that with time and support PADL would embed. Competing priorities in an inadequately resourced healthcare setting made PADL challenging. Professional bodies formally defining PADL as a core role for their HCWs would increase engagement with PADL. The PADL champion role was identified as key to the implementation of PADL. Conclusions: Competing priorities were limiting PADL engagement and as such PADL needs to be a core part of a HCW's role for it to be prioritized. The champion is required to support PADL as a shared responsibility and needs to be available until the process is embedded into ways of working.