Preventable adverse drug events in a hospital Emergency Department

Objective. To determine the incidence and evaluate the preventability of adverse drug events (ADE) associated with visits to the Emergency Department at our hospital and subsequent hospital admissions. Methods. A six-month observational study was conducted at an Emergency Department in a University Teaching Hospital (October 15th, 1995, to April 15th, 1996). The parameters influencing the preventability were identified by means of a multivariate logistic regression analysis. Results. a total of 776 ADEs (2.25%) were detected out of a total of 33,975 patients attended at the Emergency Department; 178 patients were admitted. a total of 322 cases (43.3%) were classified as preventable and were graded as mild (37.1%), moderate (32.5%), severe (27.4%), and fatal (3%). The logistic regression analysis showed that preventability was related to drugs with a narrow therapeutic index (NTI) (OR: 10.12;. 95%CI: 5.36-19.07), type A ADE (OR: 4.65; 95%CI: 2.79-7.78), age greater than or equal to 65 years (OR: 3.04; 95%CI: 2.13-4.34) and self-administered medication (OR: 2.2; 95%CI: 1.32-3.65). Among admitted patients, oral anticoagulants, NSAIDs, digoxin, diuretics, and insulin caused adverse events which were considered as preventable in more than 50% of cases. The errors most frequently associated with preventable ADEs included inappropriate therapy monitoring (22.5%), increased doses with NTI drugs (22.3%), absence of preventive therapy (14.3%), excessive dose according to patient's characteristics (13.4%), and inappropriate self-administered medication (10%). Conclusions. The incidence of preventable ADEs (medication errors) is high anal its severity is higher than that of non-preventable ADEs. A prompt development and implementation of measures leading to avoiding prescription errors and inappropriate treatment monitoring, the factors identified as responsible for preventable ADEs, is clearly warranted.