Introduction: Syndromic panel assays, that is, using one test to simultaneously target multiple pathogens with overlapping signs and symptoms, have been integrated into routine paediatric care over the past decade, mainly for more severely ill and hospitalised patients. Their wider availability and short turnaround times open the possibility to apply them to non-hospitalised patients as well. In this context, it is important to trial how clinicians make use of pathogen detection data and if their early availability influences management decisions, particularly antibiotic use and hospitalisation.

Methods and analysis: Advanced Diagnostics for Enhanced QUality of Antibiotic prescription in respiratory Tract infections in Emergency rooms is an individually randomised, controlled, open-label effectiveness trial comparing the impact of a respiratory pathogen panel assay (BIOFIRE Respiratory Panel 2.1plus) used as a rapid syndromic test on nasopharyngeal swabs in addition to the standard of care versus standard of care alone. The trial will 1:1 randomise 520 participants under the age of 18 at 7 paediatric emergency departments in 5 European countries. Inclusion criteria for the trial consist of two sets, with the first describing respiratory tract infections in paediatric patients and the second describing the situation of potential management uncertainty in which test results may immediately affect management decisions. Enrolment started in July 2021 and is expected to be completed in early 2024. We will perform a two-sample t-test assuming a pooled variance estimate to compare the log-transformed mean time on antibiotic treatment (in hours) and number of days alive out of the hospital within 14 days after study enrolment between the control and intervention arms.

Ethics and dissemination: The trial protocol and materials were approved by research ethics committees in all participating countries. The respiratory pathogen panel assay is CE marked (assessed to meet European regulations) and FDA (United States Food and Drug Administration) cleared for diagnostic use. Participants and caregivers provide informed consent prior to study procedures commencing. The trial results will be published in peer-reviewed journals and at national and international conferences. Key messages will also be disseminated via press and social media where appropriate.

Trial registration number: NCT04781530.