Co-Design and Pilot Testing of a Nurse-Led GP-Supported Self-Management Intervention for Breast Cancer Survivors with Cardiovascular Diseases: A Study Protocol.

Background/Objectives: Self-management intervention strategies are recommended to address the needs of breast cancer survivors (BCSs) who have cardiovascular diseases (CVDs). Despite the benefits, these strategies are often suboptimally implemented, resulting in inadequate cardiovascular management among BCS with CVDs. The project aims to develop a nurse-led and GP-supported self-management (NGPS) intervention to reduce cardiovascular risks in BCS with CVDs and evaluate its feasibility and potential effects in primary care settings using the double diamond co-design process and the Medical Research Council (MRC) Framework for Developing and Evaluating Complex Interventions. Methods: The study will be conducted in two phases. In phase I, an evidence-based and co-designed NGPS protocol with end-users will be preliminarily developed based on the identified research evidence, relevant theories, practice guidelines and the current practice standards in Australia. The co-design workshop(s) will involve healthcare professionals and BCSs with CVDs to further refine and validate the developed preliminary protocol. In phase II, a one-group pre-post pilot study will evaluate the feasibility of the intervention and study procedures, such as recruitment, retention, adherence, acceptability, and safety as primary outcomes. The study will also preliminarily explore the effectiveness of the intervention such as physiological measures as secondary outcomes to inform a future large-scale trial. Phase II also involves follow-up qualitative interviews to explore participants' experiences of the pre-post pilot study. The participants will be recruited from primary medical centres in Victoria. Conclusions: The findings will provide a co-designed evidence-based intervention for primary care nurses and General Practitioners (GPs) to promote long-term health outcomes for patients with both breast cancer (BC) and CVDs. Clinical registration: ClinicalTrial.gov (registration No. NCTO7313397).