First results from the ARON trial: Clinical decision tool to guide antibiotic prescribing in acutely ill children: a pragmatic cluster-randomised controlled trial in primary care

Background. Antimicrobial resistance is a global health threat. Many acutely ill children in ambulatory care are unnecessarily prescribed antibiotics. The ARON trial assessed the effectiveness of a clinical decision tool, including a validated decision tree, point-of-care C-reactive protein testing, and safety-netting advice. Methods. ARON was a pragmatic, cluster-randomised, unblinded controlled trial at 171 Belgian GP and community paediatrician practices. Using block randomisation (n=4), practices were allocated (1:1) to the decision tool or usual care. Acutely ill children 6m-12y were recruited and followed for 30 days. Co-primary outcomes were antibiotic prescribing (index consultation) (tested for superiority), recovery time, additional testing, follow-up visits, and antibiotic prescribing (after index consultation) (tested for non-inferiority with margins of 1 day, 3%, 4%, and 2%, respectively). Analyses used logistic regression, adjusting for practice clustering, study arm, and age in the intention-to-treat population; recovery time was analysed using Cox regression with the same covariates. Findings. Eighty-two practices were allocated to the intervention group and 89 to usual care. Between Feb 24, 2021, and Dec 29, 2023, 7049 participants were screened. Data from 6750 eligible children (2988 intervention, 3762 control; 3447 boys, 3302 girls, one unspecified) were analysed. The intervention significantly reduced antibiotic prescribing (index consultation): 16% vs 22%, OR 0.72 (0.55–0.94). Recovery time, additional testing, follow-up visits, and post-consultation antibiotic prescribing were non-inferior. No child died during the trial. Interpretation. The clinical decision tool reduced antibiotic prescribing without harm. Our results support its broader dissemination to improve managing acutely ill children in ambulatory care.