Root cause analysis of ambulatory adverse drug events that present to the emergency department.

Adverse drug events (ADEs) are a common reason for emergency department (ED) visits in elderly patients. This study used root cause analyses—which incorporated patient perspectives—of ED visits for ADEs to identify contributing factors related to drugs (e.g., prescribing of high-risk medications), patients (e.g., low health literacy), and the environment (e.g., poor access to care).