Suspected adverse drug events requiring emergency department visits or hospital admissions

Objective: To analyse the contribution of adverse drug events (ADEs) to the overall number of referrals or visits at an emergency department, to deter mine the proportion of more severe episodes requiring hospital admission an d to characterize the different causes of drug-related visits or admissions . Methods: A 1-year prospective collection of data on visits performed at an emergency department. All visits, observed during 1 week every month, were analyzed in order to identify suspected ADEs. The effects of age and sex on the frequency of ADE-related visits and admissions were evaluated. All pat ients hospitalized because of an ADE were followed up in order to collect i nformation about progress and outcome of the events, which were also assess ed in terms of avoidability. Results: Among the 5497 patients who visited the Emergency Department over 1 year, 235 (4.3%) experienced an ADE, 45 of these (19.1%) were subsequentl y hospitalized, among whom there were five deaths. Dose-related therapeutic failures were the main causes of drug-related admissions (55.6%), whereas adverse drug reactions caused the most frequent drug-related visits to the Emergency Department (63.8%). Although the frequency of drug-drug interacti ons leading to a visit to the Emergency Department was small (3.8%), this t ype of event was more severe, because most of these patients were hospitali zed. No age/sex effect was observed in the proportion of ADE-related hospit al admissions. Twenty-five (1.4% of the total admissions) of the 45 ADE rel ated admissions were evaluated as preventable, contributing by more than 61 % of the overall length of hospital slay. Conclusion: The high proportion of drug therapeutic failures leading to an admission highlights the need for public education, particularly to prevent non-compliance.