Adverse drug events in emergency department population: A prospective Italian study

Introduction: Several studies were performed to evaluate adverse drug events (ADEs) incidence among inpatients, while few data are available on ADEs in outpatient setting and on related hospital admissions. Particularly, only one investigation was conducted on this important health issue in Italy. Aims of the Study: To determine ADE incidence and ADE-related hospital admissions among Emergency Department (ED) visits, and to identify risk factors of developing ADE requiring ED visit. Methods: During the year 2000 we conducted a prospective study in 2 observational periods of 10 days each in 22 Italian EDs. Demographic, clinical and pharmacological data about all patients visiting ED were collected by trained and qualified monitors. Records related to ADE were analysed and validated by a specific scientific committee. Results: Among 18 854 patients included into the study, 629 (3.3% of total sample) reported at least one ADE, of which 244 resulted in serious events. Patients affected by ADE were significantly more likely to be hospitalised compared with the total sample (30.7% vs 23.7%, p ≤ 0.0001), and accounted for 4.3% (193 cases) of total hospitalisations. Female gender and old age were factors significantly associated with an ADE, while patients with serious ADEs were more likely to be male and older than the ADE sample. NSAIDs and antibiotics were the drug types most involved in ADE with 104 (16.5% of total ADE visits) and 81 cases (12.9%), respectively. ADE affected mostly skin (213 ADE visits) and the gastrointestinal system (211). Conclusion: Older patients and females result to be at higher risk to develop ADE leading to ED. The high ADE-related hospitalisation incidence highlights need for prevention planning targeted to reduce impact of ADE within general population.