From adoption to implementation: paediatricians' experiences with C-reactive protein point-of-care testing in the community setting.

Background: The ARON trial demonstrated the (cost-)effectiveness of a multifaceted antimicrobial stewardship intervention including C-reactive protein (CRP) point-of-care testing (POCT) for children with acute illness in Belgian general practice and community-based paediatrics. However, little is known about how CRP POCT is experienced in paediatric practice in the community, particularly in the absence of structural support and a formal legal framework. The objective of the study was to explore how paediatricians use, interpret, and adapt CRP POCT in real-world community-based practice and to identify factors influencing its sustained implementation. Methods: We conducted semi-structured interviews with Belgian paediatricians experienced in using CRP POCT, either through participation in the ARON trial or as part of routine care, allowing us to capture both protocol-guided and routine practice implementation experiences. Participants were recruited using a mixed sampling approach, combining convenience and snowball sampling. Data were analysed thematically, guided by two complementary implementation science frameworks: the Consolidated Framework for Implementation Research and Normalization Process Theory. Results: Fifteen paediatricians were interviewed. Participants generally viewed CRP POCT positively, but reported navigating substantial implementation challenges, including the absence of reimbursement and unclear logistical routes. Use frequently extended beyond its intended diagnostic purpose, with CRP POCT employed to support communication with parents, provide reassurance or legitimise treatment decisions. Interpretation and confidence evolved through repeated use and informal peer exchange. In the absence of formal feedback or training, clinicians relied primarily on experiential learning to refine their practice. Conclusions: These findings illustrate both the flexibility and fragility of self-directed implementation in the absence of system-level support. While paediatricians valued CRP POCT, translating early adoption into sustained and equitable routine use in community paediatric care will require formal guidance, financing structures, and shared interpretative frameworks.