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What’s New in the Patient Safety World

November 2019

Emergency Department Trigger Tool



Trigger tools improve our ability to identify adverse events. The beauty of trigger tool methodology (see our Patient Safety Tips of the Week for October 30, 2007 “Using IHI's Global Trigger Tool” and April 15, 2008 “Computerizing Trigger Tools”) is that it allows you to screen a large number of records that potentially have the item you are really looking for. Then in the subset of records that contain the “trigger” you can then do manual chart review to verify details. It basically streamlines what would otherwise be a very labor- and time-intensive process that would not otherwise be practical.


Historically, identification of adverse events in emergency departments (ED’s) has relied primarily on reporting systems. That leads to an underestimation of adverse events. Recently there have been an interest in the use of trigger tools to identify adverse events in emergency departments.


Griffey et al. (Griffey 2019) looked at the impact of 97 individual “triggers” that could identify cases for review from the electronic medical record. That identified over 76,000 ED visits with at least one trigger. They then performed manual review on a subset of 1726 records to determined whether adverse events had occurred. The reviews found 21.6 adverse events per 100 records. There was good correlation between the automated qurery and the manual review (sensitivity >70% for 80 triggers; specificity >92% for all). They then looked at whether the number of triggers or use of “weighted” triggers could improve the yield. An estimated 10.3% of records with greater than 1 of these triggers would include an adverse event in the ED, but selecting only records with greater than or equal to 4 or greater than or equal to 9 triggers improves yield to 17% and 34.8%, respectively. Further enhancements, such as trigger weighting, enhanced the yield to as high as 52%. Use of trigger tools like these would obviously make the burden of manual record review much less onerous.


Prior work by Griffey and colleagues described how the trigger tools were developed (Griffey 2016) and how they performed in a multicenter pilot study (Griffey 2018).


A study from Taiwan (Lee 2019) prospectively evaluated a monitoring system that combined 2 reporting methods and 5 trigger tool methods to capture adverse events in the ED of an academic medical center. Of adverse events identified, 77.2% were identified using reporting methods, 26% using trigger tool methods, and 3.2% using both methods. Most patients (81.7%) incurred temporary, minor physical impacts. Compared with reporting methods, trigger tool methods had a lower positive predictive rate to identify adverse events overall but a greater proportion of adverse events occurring during the preinterventation and postintervention phases, and more cases of severe physical impact or death. The authors conclude that combined use of the different methods had synergistic benefits for monitoring adverse events in the ED.


Obviously, use of multiple methods to identify adverse events in the ED (as well as other settings) improves the yield. But use of trigger tools has great promise in improving our ability to identify such events.



Some of our prior columns on trigger tool methodology:






Griffey RT, Schneider RM, Todorov AA. The Emergency Department Trigger Tool: A Novel Ap.roach to Screening for Quality and Safety Events. Annals of Emergency Medicine 2019; Volume 0, Issue 0 Published October 14, 2019



Griffey RT, Schneider RM, Adler LM, et al. Development of an Emergency Department Trigger Tool Using a Systematic Search and Modified Delphi Process. Journal of Patient Safety 2016; Publish Ahead of Print June 16, 2016



Griffey RT, Schneider RM, Sharp BR, et al. Multicenter Test of an Emergency Department Trigger Tool for Detecting Adverse Events. Journal of Patient Safety 2018; Publish Ahead of Print July 18, 2018



Lee W-H, Zhang E, Chiang C-Y, et al. Comparing the Outcomes of Reporting and Trigger Tool Methods to Capture Adverse Events in the Emergency Department

Journal of Patient Safety 2019; 15(1): 61-68





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