Validation of Registry-Based Indicators for Postdiagnostic Antibiotic Decisions in Pediatric Febrile Urinary Tract Infection

BackgroundElectronic prescribing registries are widely used for antimicrobial stewardship surveillance. Existing indicators predominantly measure structure or process, while validated outcome indicators remain rare. The present study evaluates how well rule-based measures capture clinically meaningful postdiagnostic antibiotic decision making in pediatric febrile urinary tract infection. MethodsWe conducted a retrospective, multicenter validation study including all empirically treated febrile UTI episodes across three Swedish pediatric emergency departments. Prescribing outcomes were classified using registry rules and compared with outcomes determined by clinician review and laboratory findings. Guidance Ratio (GR) and Discontinuation Ratio (DR) were calculated monthly and in aggregate for both clinically validated- and registry rule classifications. ResultsIn total, 909 febrile UTI episodes were included across all sites. The rule-based GR was 49%. GR increased consistently with stronger diagnostic evidence. Among the 431 episodes with clinician-adjudicated follow-up, 63% resulted in guided treatment; 28% discontinued treatment, and 9% lacked follow-up documentation. The rule-based algorithm showed a sensitivity of 0.78 and a specificity of 1.00 for identifying guided outcomes. Monthly rule-based GR tracked validated temporal patterns but underestimated absolute values. A calibration function substantially improved agreement. ConclusionsRule-based indicators captured overall prescribing patterns but underestimated the level of prescribing concordant with guidelines. Validation against clinician reviewed reference data enabled calibration and improved the interpretability of indicators based on registry data for antimicrobial stewardship.