Enhancing the insights of the Patient‐and care‐related benefits of amyloid PET imaging ‐ ENABLE ‐ study through a process evaluation: a study protocol

Abstract Background Amyloid PET imaging is an established diagnostic tool for Alzheimer's disease, but its successful integration into clinical practice requires a comprehensive understanding of its impact on patients and the healthcare system. In 2022, the coverage with evidence development (CED) ENABLE study has been approved by the German Federal Joint Committee (trial registration: DRKS00030839). The study is scheduled to start in early 2024. Primary outcome of ENABLE is the change in patients' functional abilities at 18 months after diagnosis with amyloid PET versus without amyloid‐PET. Here we describe the design of an ENABLE sub‐study aimed at performing a process evaluation. Method We will conduct an outcome and process evaluation using a pre‐post descriptive design nested in ENABLE (Figure), based on the Medical Research Council's Process Evaluation (PE) framework. The PE will focus on acceptability and reach of the target groups of patients and care providers, as well as fidelity of delivery (% of adherence to protocol, study duration), contextual changes and mechanisms (e.g., ability to mirror routine care). We will collect patients’ data independently, but in parallel with ENABLE, using interviews, surveys and checklists to assess acceptance of the intervention, fidelity of adherence to the follow‐up procedures, perceived benefits and challenges. Healthcare providers and administrators will be interviewed to identify implementation hurdles and facilitators, contextual factors influencing uptake and underlying mechanisms. For data analysis we will employ a mixed‐methods approach. Result Expected outcomes will include acceptability and adherence, barriers and facilitators to implementation, contextual factors influencing implementation, perceived utility of the intervention by patients and providers, and mechanisms by which the intervention can be delivered as part of normal care. Conclusion This process evaluation can inform researchers on how to design future CED studies to be implemented into clinical care. The lessons learned during the development and approval process of the ENABLE project in Germany, as well as its process evaluation, can benefit other European CED studies and policy‐makers stakeholders in making informed decisions. Likewise, these findings can be generalized beyond the context of amyloid PET to other diagnostic biomarkers, ultimately improving the diagnosis and management of Alzheimer's disease.