Adverse drug event rate in Israeli hospitals: Validation of an international trigger tool and an international comparison study

Background: Adverse drug events (ADEs) are a major cause of morbidity and mortality worldwide. Hence, identifying and monitoring ADEs is of utmost importance. The Trigger Tool introduced by the Institute of Healthcare Improvement in the United States has been used in various countries worldwide, but has yet to be validated in Israel. Objective: To validate the international Trigger Tool in Israel and to compare the results with those generated in various countries. Methods: A retrospective descriptive correlative analysis surveying four general hospitals in Israel from different geographical regions was conducted. Patient medical charts (n=960) were screened for 17 established triggers and confirmed for the presence of an ADE. Trigger incidence was compared to the actual ADE rate. Further comparison among countries was conducted using published literature describing Trigger Tool validation in various countries. Results: A total of 421 triggers in 279 hospitalizations were identified, of which 75 ADEs in 72 hospitalizations (7.5%) were confirmed. In addition, two ADEs were identified by chart review only. Mean positive predictive value was 17.81% and overall sensitivity was 97%. We found 1.54 ADEs for every 100 hospitalization days, 7.8 ADEs per 100 admissions, and 1.81 ADEs for every 1000 doses of medication. Of the 77 ADEs identified, 22.7% were defined as preventable. Conclusions: Our results support the Trigger Tool validity in Israel as a standardized method. Further studies should evaluate between hospital and region differences in ADE rate, in particular for the preventable events.