Optimising the care pathway of febrile children via capillary C-reactive protein assay in primary care: the CRP-CAP cluster randomised stepped-wedge study protocol

INTRODUCTION: Fever is the leading reason for consultation among children in general practice. 20% of febrile children require additional tests to distinguish between viral infections and severe bacterial infections. Point of care capillary C-reactive protein (POC CRP) testing provides on-site results within 5 min but remains underutilised in primary care settings in France. This study will demonstrate how the use of POC CRP could optimise the care pathway for febrile children, saving time for physicians and patients, and making economic savings. METHODS AND ANALYSIS: This is a multicentre, prospective, cluster-randomised stepped-wedge trial that will take place from September 2025 to March 2026. The required sample size is estimated at 420 patients. The primary outcome is the difference in referral rates to facilities equipped for emergency laboratory testing (medical biology laboratories, emergency departments) when using POC CRP versus standard care. The study will be conducted in primary care practices and out-of-hours clinics in south France among febrile children aged 3 months to 15 years, over the 6-month viral and bacterial epidemic period. A cost-consequence analysis and a budget impact assessment will also be performed. ETHICS AND DISSEMINATION: The protocol was approved by the Ile de France VII Committee for the Protection of Persons (2024-A02844-43), the French Advisory Board on Medical Research Data Processing and the French Personal Data Protection Authority. The study was prospectively registered on clinicaltrials.gov. TRIAL REGISTRATION NUMBER: NCT06910631.