Adverse events following an emergency department visit

Background: Many studies demonstrate a high rate of treatment-related adverse outcomes or adverse events. No studies have prospectively evaluated adverse events in patients discharged home from the emergency department (ED). Objective: To describe the types of adverse events in patients discharged home from an ED. Patients: Patients who were sent home directly from the ED of an urban, academic teaching hospital in Ottawa, Canada. Methods: Patient records were reviewed to identify demographic and medical history information. Two weeks following the ED visit, patients completed a standard telephone interview to record post ED visit outcomes. Two physicians reviewed outcomes to identify all adverse events and their cause. Results: Follow-up was complete for 399 of 408 enrolled patients. The median age was 49 years (interquartile range 36-68) and 50% were male. The most common diagnosis was chest pain'', occurring in 74 patients (18%), followed by bone and joint disorders'' in 55 patients (14%). 24 patients experienced an adverse event (incidence 6% (95% CI 4% to 9%)), of which 17 were preventable (incidence 4% ( 95% CI 3% to 7%)). Five of the unpreventable adverse events were medication side effects and two were minor, procedure-related complications. Of all 24 adverse events, 15 (63%; 95% CI 43 to 79%) led to an additional ED visit or a hospitalisation. Preventable adverse events occurred in 5 of 78 chest pain patients (incidence 6% (95% CI 3% to 14%)). Conclusion: Most adverse events occurring following an ED visit are preventable and often relate to diagnostic or management errors.