Trends and Factors Associated with Medication-Related Patient Safety Incidents Reported in Korean Hospitals: A Retrospective National Analysis (2020–2024)

Background: Medication-related patient safety incidents are among the most common and preventable sources of harm in healthcare systems worldwide. In Korea, medication incidents have consistently ranked among the most frequently reported patient safety events since the implementation of the national patient safety reporting system. However, national-level evidence examining recent trends and factors associated with clinically significant harm remains limited. Methods: This retrospective observational study analyzed medication-related patient safety incidents reported to the Korea Patient Safety Reporting & Learning System (KOPS) from 2020 to 2024. KOPS operates as a hybrid system with voluntary reporting for general incidents and mandatory reporting for severe events since 2021. Harm severity was dichotomized into near-miss incidents and adverse/sentinel events. Of 36,281 reported incidents, 9495 were included after excluding cases with missing key variables. This dichotomization was applied to distinguish clinically meaningful harm and support robust statistical analysis. Results: Medication-related incidents showed an increasing trend in reported cases over time (annual percent change: 15.38%; 95% CI, 6.0–25.6%). Among the analyzed cases, 21.2% resulted in adverse/sentinel events. These events were more frequently observed in large hospitals, emergency and critical care settings, and during evening and nighttime periods. This increase may reflect changes in reporting practices following mandatory reporting policies, as well as potential changes in medication-related risks. Conclusions: Reported medication-related incidents are increasing, and a substantial proportion are associated with harm. However, these findings should be interpreted cautiously, as they reflect reported incidents rather than the true incidence of medication errors. Targeted strategies focusing on high-risk settings (emergency/critical care), vulnerable patient groups, and off-hour periods may be needed. Integrating risk-based approaches into national patient safety policies may help reduce preventable harm.