Participatory development and feasibility study of a digital intervention for detecting and treating bio-psycho-social needs of long-term cancer survivors: study protocol of the DELPHIN study.

INTRODUCTION: Long-term cancer survivors may suffer from significant bio-psycho-social burden even years after treatment. Yet, a structured approach to detect and address bio-psycho-social burden of long-term cancer survivors in primary care is missing in Germany, although family physicians are the primary medical contact for most patients. In this paper, we describe the DELPHIN study aiming to develop and test a structured care model for long-term cancer survivors. The DELPHIN study and intervention will facilitate networking of regional medical and non-medical services. This protocol describes the intervention as well as the pilot study.

METHODS: The DELPHIN study comprises a developmental and a feasibility phase. In the developmental phase, we will assess (1) the current care needs of long-term cancer survivors (n=1000) using a cross-sectional questionnaire survey; (2) in an additional cross-sectional questionnaire survey, we will address medical and non-medical care providers to assess current care practice for this patient group (n≥250); (3) a qualitative interview study with both long-term cancer survivors (n=12) and family physicians (n=10) will assess patients' needs and barriers for effective care. Results will then be triangulated to inform development of the DELPHIN intervention. The intervention shall include the following elements: the DELPHIN mobile app for patients with a digital screening tool, a digital treatment plan, a survivorship passport and information on regional medical and non-medical providers. Additionally, a DELPHIN website and a DELPHIN eLearning tool for family physicians will be developed. The subsequent feasibility study will follow 100 long-term cancer survivors using the DELPHIN app for 4 months, with two assessments (t=baseline; t=4 months follow-up) regarding the usability of the app and their health-related quality of life. The eLearning tool will be tested by 50 family physicians using three measurement points to evaluate learning success (t=before; t=directly after eLearning; t=after 4 weeks).

DISCUSSION: The DELPHIN study seeks to address cancer survivors' unmet bio-psycho-social needs through implementing a digital mobile application. Positive results in the feasibility study will provide the basis for a future effectiveness study and integration into routine care.

ETHICS AND DISSEMINATION: The study was reviewed by the Ethics Committee of the University of Bonn, Germany (No: 2024-409 BO) which did not object to the study.

TRIAL REGISTRATION NUMBER: DRKS00035726.

© Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.

PMID: 42014153