Impact of a Hospital Information System-Integrated Automated Dispensing Cabinet on Medication Use and Safety in a Tertiary Hospital Emergency Department: A Prospective Before-and-After Study

Background/Objectives: Emergency departments (EDs) are particularly prone to medication errors because of urgent treatment environments and high decision density. Automated dispensing cabinets (ADCs) integrated with the hospital information system (HIS) may improve medication safety, yet real-world evidence in centralized-pharmacy settings remains limited. This study evaluated the impact of an HIS-integrated ADC on medication use, medication errors, and nurses’ perception of safety in the ED of a Korean tertiary hospital. Methods: In this prospective before-and-after study, prescribing patterns, medication storage, and related costs were compared in the two months before (Phase 1; September–October 2019) and after (Phase 2; May–June 2020) ADC installation. Medication errors reported through the hospital safety incident reporting system were analyzed over corresponding 6-month windows from July 2019 to June 2020. Long-term sustainability was assessed using follow-up data collected from October to November 2023 (Phase 3), and all 46 ED nurses completed a 5-point Likert-scale survey on perceived medication safety. Results: Daily injectable prescriptions were unchanged (221.1 ± 34.6 vs. 227.7 ± 35.2; p = 0.301), whereas returned injectable prescriptions increased (17.9 ± 5.9 vs. 25.1 ± 6.0; p < 0.001) and non-injectable prescriptions decreased (163.1 ± 42.2 vs. 140.0 ± 22.7; p < 0.001). The number of medication items stored in the ED storage room declined by 95.6%, with a 92.5% reduction in related maintenance cost. Total medication errors decreased from 41 (74.5%) before to 14 (25.5%) after implementation (p < 0.001), with the largest reduction in delivery errors (17 [30.9%] to 2 [3.6%]). These improvements were sustained at the three-year follow-up. Nurses reported high overall satisfaction with medication safety (4.27 ± 0.62 on a 5-point Likert scale). Conclusions: Implementation of an HIS-integrated ADC in the ED was associated with improved prescription patterns, fewer reported medication errors, and enhanced perceived medication safety. In addition, these improvements were sustained over time, indicating stable and consistent implementation of the ADC system. Nurses also reported improved perceptions of medication safety.