Feasibility, acceptability, and usability of a patient decision aid for participation in the DAHANCA 35 proton radiotherapy trial: A qualitative study

Background Clinical trial participation in oncology remains low, despite its importance for advancing treatment. Patients are often asked to consider trial participation in emotionally and cognitively demanding situations, which may limit their ability to engage with complex information and relate decisions to their values and life context. Patient decision aids (PtDAs) may support informed, value-based decision-making, but their feasibility in clinical trial settings warrants further exploration. Objective To qualitatively assess the feasibility of integrating a clinical trial PtDA into routine trial communication and to explore its acceptability and usability in practice. Methods A qualitative feasibility study using interpretive description methodology was conducted. Semi-structured telephone interviews were performed with 11 patients and 14 healthcare professionals involved in a Danish randomised controlled trial comparing photon and proton radiotherapy. Data were analysed inductively. Results Integration of the PtDA into clinical workflows was feasible. However, its acceptability and usability varied depending on how it was introduced and embedded in clinical interactions. Patients engaged with the PtDA in different ways; some used it independently or with family members, while others required clinician support. Participants described the PtDA as supporting understanding and dialogue and as being versatile in different settings, although some needed additional interaction with a clinician to use it meaningfully. Conclusion A clinical trial PtDA can be integrated into routine practice, but its usefulness depends on active implementation and clinician engagement. PtDAs should be implemented as part of broader interventions to support person-centred decision-making and care in clinical trial contexts.