Critical Review, Development, and Testing of a Taxonomy for Adverse Events and Near Misses in the Emergency Department.

Objectives: An adverse event (AE) is a physical harm experienced by a patient due to health care, requiring intervention. Describing and categorizing AEs is important for quality and safety assessment and identifying areas for improvement. Safety science suggests that improvement efforts should focus on preventing and mitigating harm rather than on error, which is commonplace but infrequently leads to AEs.