Evaluation of accuracy of IHI Trigger Tool in identifying adverse drug events: a prospective observational study

Aims: Adverse drug events (ADEs) can seriously compromise the safety and quality of care provided to hospitalized patients, requiring the adoption of accurate methods to monitor them. We sought to prospectively evaluate the accuracy of the triggers proposed by the Institute for Healthcare Improvement (IHI) for identifying ADEs.

Methods: A prospective study was conducted in a public university hospital in 2015 with patients over the age of 18. Triggers proposed by IHI and clinical alterations suspected to be ADEs were searched daily. The number of days in which the patient was hospitalized was considered as unit of measure to evaluate the accuracy of each trigger.

Results: A total of 300 patients were included in this study. Mean age was 56.3 years (standard deviation (SD) 16.0), and 154 (51.3%) were female. The frequency of patients with ADEs was 24.7% and with at least one trigger was 53.3%. From those patients who had at least one trigger, the most frequent triggers were antiemetics (57.5%) and 'abrupt medication stop' (31.8%). The sensitivity of triggers ranged from 0.3 to 11.8% and the positive predictive value ranged from 1.2 to 27.3%. Specificity and negative predictive value were greater than 86%. Most patients identified by the presence of triggers did not have ADEs (64.4%). No triggers were identified in 40 (38.5%) ADEs.

Conclusions: IHI Trigger Tool did not show good accuracy in detecting ADEs in this prospective study. The adoption of combined strategies could enhance effectiveness in identifying patient safety flaws. Further discussion might contribute to improve trigger usefulness in clinical practice.