Community Health Workers for Primary Healthcare Access (COMPASS), integrating a comprehensive CHW intervention in primary healthcare in Belgium: a cluster-randomized controlled trial protocol.

BACKGROUND: Inequality in access to Primary Health Care (PHC) is increasing in Belgium, in contrast to an overall decreasing trend throughout the European Union. A (cost-)effective solution for access-to-care challenges for people who experience challenges accessing primary healthcare (PECAP) in Belgium is needed; to address this knowledge gap, the research team drew on lessons from the CHW model in the Family Health Strategy (Brazil) and Re-engineering PHC (South Africa), in line with reciprocal innovation, to develop the Community Health Workers for Primary Healthcare Access (COMPASS) intervention. METHODS: The COMPASS study is a cluster-randomized controlled trial (cRCT) in the city of Antwerp, Belgium. Eighteen general practitioner (GP) practices are randomly allocated to the intervention or control arm. In each GP practice, we aim to enrol 21 PECAP, resulting in a total of 378 adult PECAP in the cRCT. Recruitment of study participants commenced on November 28th, 2024, and was completed by June 11th, 2025. In the control arm, participants will receive standard care. In the intervention arm, CHWs will offer a comprehensive package of support in addition to the current standard of care to an individual living in socio-economically vulnerable circumstances during home visits over the course of 12 months. A longitudinal mixed methods design is adopted. To assess the effectiveness of the cRCT, methods including cluster-level analysis as well as linear and generalized linear mixed models will be used. The primary study outcomes of the quantitative research will comprise self-perceived health. Secondary outcomes include health care use, health-related quality of life, health literacy, empowerment, and financial burden of health care. An economic evaluation alongside the cRCT will be conducted to assess the cost-effectiveness of the intervention in addition to usual care, compared to standard care alone. To assess the acceptability and feasibility, as well as the underlying mechanisms of the impact on access to care, qualitative data (in-depth interviews, focus group discussions, and participant observations) will be collected at two time points. DISCUSSION: Via a comprehensive CHW intervention in collaboration with GP practices, the COMPASS cRCT aims to provide crucial evidence on the (cost-)effectiveness, acceptability, and feasibility of an intervention delivered by CHWs linked to GP practices in communities with PECAPs in Belgium. If proven effective, this model may offer a scalable strategy to mitigate healthcare access disparities across Belgium.