Characterization of Adverse Events Detected in a Large Health Care Delivery System Using an Enhanced Global Trigger Tool over a Five‐Year Interval

Objective To report 5 years of adverse events ( AE s) identified using an enhanced Global Trigger Tool ( GTT ) in a large health care system. Study Setting Records from monthly random samples of adults admitted to eight acute care hospitals from 2007 to 2011 with lengths of stay ≥3 days were reviewed. Study Design We examined AE incidence overall and by presence on admission, severity, stemming from care provided versus omitted, preventability, and category; and the overlap with commonly used AE ‐detection systems. Data Collection Professional nurse reviewers abstracted 9,017 records using the enhanced GTT , recording triggers and AE s. Medical record/account numbers were matched to identify overlapping voluntary reports or AHRQ Patient Safety Indicators ( PSI s). Principal Findings Estimated AE rates were as follows: 61.4 AE s/1,000 patient‐days, 38.1 AE s/100 discharges, and 32.1 percent of patients with ≥1 AE . Of 1,300 present‐on‐admission AE s (37.9 percent of total), 78.5 percent showed NCC ‐ MERP level F harm and 87.6 percent were “preventable/possibly preventable.” Of 2,129 hospital‐acquired AE s, 63.3 percent had level E harm, 70.8 percent were “preventable/possibly preventable”; the most common category was “surgical/procedural” (40.5 percent). Voluntary reports and PSI s captured <5 percent of encounters with hospital‐acquired AE s. Conclusions AE s are common and potentially amenable to prevention. GTT ‐identified AE s are seldom caught by commonly used AE ‐detection systems.