Evaluation of the Allergy Fact Checker, a clinical decision support system for non-invasive beta-lactam delabeling: a mixed-methods study.

Penicillin allergy delabeling strategies are time- and resource-consuming. In this mixed-methods study, we evaluated the 'Allergy Fact Checker', a novel clinical decision support system designed to identify patients with uneventful re-exposure to penicillins, enabling delabeling without additional testing. The intervention involved implementation of the tool, pharmacist-led review of alerts, and physician contact. An interrupted time series analysis assessed delabeling outcomes, and physicians were interviewed to explore implementation barriers. The Allergy Fact Checker identified 8.9% (164/1850) of patients with a penicillin allergy label. The delabeling rate increased from 12% to 60% (OR 6.8 (95% CI 1.3-35, P = 0.02)). Addressing one alert took 5 min ( ± 3 min). Reported barriers included workload and limited knowledge of the allergy label removal process. By streamlining the identification process, the Allergy Fact Checker offers a low-resource, scalable solution that significantly improves delabeling and integrates easily into existing clinical workflows.