Psychosocial Burden and Supportive Care Needs of Informal Caregivers in Specialist Palliative Care: Protocol of a Multicenter Longitudinal Cohort Study to Identify Trajectories and Validate the Multidimensional Screening Tool CAREPAL-8

Background: Informal caregivers (ICs) of patients with advanced incurable diseases experience substantial psychosocial burden and unmet needs. However, efficient screening tools to identify ICs at risk of developing clinically relevant psychosocial problems are lacking. Additionally, most existing studies on burden and needs use cross-sectional designs, failing to capture the dynamic and evolving nature of caregiving. Objective: This study aims (1) to explore the trajectories of ICs' psychosocial burden and supportive care needs during specialist palliative care (SPC) and factors associated with these trajectories and (2) to validate the 8-Item Screening Tool for Family Caregiver Burden in Palliative Care (CAREPAL-8), an 8-item multidimensional screening tool developed to categorize ICs into clinically relevant risk groups regarding dimensions of burden. Methods: This prospective, multicenter, longitudinal cohort study is conducted across 16 study centers in Germany, involving palliative care wards, multiprofessional SPC teams in hospitals, and specialist palliative home care teams. Data are collected upon the patient's admission to SPC (baseline) and weekly for up to 10 weeks, using validated questionnaires and the CAREPAL-8. Based on a priori sample size calculation, we aim to collect data from 510 ICs at baseline and on at least 1 additional follow-up measurement point. To minimize participant burden, a planned missing data design is used for follow-up questionnaires. Data analyses will include growth mixture models for study aim 1 and determination of convergent validity and sensitivity to change of the CAREPAL-8 for study aim 2. Results: Data collection commenced on July 31, 2023. Results are expected from March 2026. Conclusions: This study aims to provide comprehensive insights into the trajectories of IC burden and needs in SPC. The validation of the CAREPAL-8 could offer a brief screening tool to classify ICs according to different risk profiles, enabling targeted support. Furthermore, the planned missing data design may enhance data quality while reducing participant burden, potentially serving as a model for similar studies in vulnerable populations.