Pediatric medication-related incidents in Japan: a nationwide observational study of severity and factors associated with severe patient harm.

UNLABELLED: Children are particularly vulnerable to medication-related harm. However, most previous research has focused on prescribing errors, leaving incidents occurring during downstream stages of the medication-use process insufficiently well characterized. We determined the epidemiology of pediatric medication-related incidents in Japan and examined factors associated with severe patient harm. This retrospective cross-sectional study analyzed nationwide incident reports from the Japan Council for Quality Health Care (JCQHC) Safe Master database involving patients aged 0 to 19 years reported between 2013 and 2024. Incidents were classified by medication-use stage and error type. Severe incidents (severity grade ≥ 3b) were identified, and associated factors were evaluated by multivariable modified Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs). Among the 54,310 incident reports, 546 pediatric medication-related incidents were identified, including 178 (32.6%) that were severe. Incidents occurring during preparation and administration accounted for 67.9% of all incidents and were associated with a higher prevalence of severe harm among reported incidents (aPR, 2.03; 95% CI, 1.38-2.98). Extravasation occurred in 35 incidents, of which 29 (82.9%) were severe. Nurse-related incidents were associated with a lower prevalence of severe harm than physician-related incidents (aPR, 0.55; 95% CI, 0.42-0.72). Patient age, time of day, neonatal intensive care unit (NICU) location, physician experience, and workload were not significantly associated with severe harm. CONCLUSION: Preparation and administration were frequently reported medication-use stages and were associated with a higher prevalence of severe harm. Pediatric medication safety strategies should extend beyond prescribing toward system-level interventions targeting preparation, administration, and monitoring. WHAT IS KNOWN: • Children are particularly vulnerable to medication-related harm, and previous pediatric medication safety research has focused predominantly on prescribing errors. • Evidence regarding severe medication-related incidents occurring during downstream medication-use stages remains limited, particularly from nationwide studies. WHAT IS NEW: • In this 12-year nationwide Japanese study, incidents occurring during medication preparation and administration (not prescribing) were associated with a higher prevalence of severe harm among reported incidents. • Severe extravasation occurred predominantly in younger children, highlighting monitoring of intravenous access sites as a key target for pediatric safety.