Lay summary
Apparent inequities are seen in the burden of breast cancer, with worse outcomes for Māori and other structurally marginalised groups. These groups also experience poorer access to palliative care services. Increasing accessibility to such services is central to ensuring equitable access to options for dying well. To achieve this, we need a clear understanding of the completeness and reliability of hospice care data. Our aim is to understand the use of hospice care data in breast cancer research. We will: (i) review existing literature to identify what types of hospice and palliative care data have been used previously; (ii) engage with key stakeholders with expertise in breast cancer and end-of-life/palliative/hospice care to further our understanding of the benefits and possible pitfalls associated with hospice care data to inform strategies to increase access to care.