Voluntary event reporting (VER) systems are required in most hospitals, but their effectiveness is limited if adverse events (AE) go unreported. In this study, researchers compared rates of AE submitted to the VER against those identified using the Global Assessment of Pediatric Patient Safety (GAPPS) trigger tool to identify disparities based on patient characteristics (i.e., weight, race, English proficiency). The GAPPS tool identified 37 AE in patients with limited English proficiency; none of these were reported to the VER system, suggesting a systematic underreporting of AE in this population.