Evaluation of dyadic psychoeducational interventions for people with advanced cancer and their informal caregivers (diadic): an international randomized controlled trial
Background: Advanced cancer affects millions of Europeans each year. The provision of adequate and cost-effective psychosocial and educational support for both patients and their frequently overburdened family caregivers is highly relevant from an economic, a healthcare and a prevention perspective.  Aims: The DIAdIC project is an interdisciplinary, cross-national project to evaluate the effectiveness and cost-effectiveness of two psycho-educational dyadic interventions, i.e. interventions that target the patient and family caregiver together. One intervention is a web-based e-health intervention, one is nurse-led face-to-face intervention. Secondary aims are to assess the interventions' effects on vulnerable subgroups (e.g. people with a lower socioeconomic position), their effectiveness in different healthcare systems, and their suitability as perceived by end-users.   Concept and methods: The two interventions are tailored to dyads' needs and have 5 core components: (1) supporting family involvement, (2) reducing hopelessness, (3) increasing coping effectiveness, (4) reducing uncertainty and (5) teaching symptom management. They are based on existing interventions, developed in the USA, that have been shown to improve quality of life of both patient and family caregiver. The effectiveness of each of the interventions (compared to care as usual) will be assessed by way of an international randomized controlled trial in people with advanced cancer and their primary informal carers. The project includes a full health-economic evaluation and a thorough process evaluation.   Impact: The project advances the state of the art in several ways, e.g. by providing innovative healthcare interventions (including a eHealth solution) that embrace the philosophy and principles of early palliative care. The interventions will be suitable for implementation across diverse healthcare systems. Public involvement methods ensure the input of stakeholders throughout the project.