The accuracy of the Global Trigger Tool is higher for the identification of adverse events of greater harm: a diagnostic test study.

BACKGROUND: Global Trigger Tool (GTT) of the Institute for Healthcare Improvement (IHI) has been used as a measurement strategy for patient safety by several institutions and national programs. Although the greater ability of the GTT to identify adverse events (AEs) compared to other methods has already been demonstrated, there are few data on its accuracy and studies suggest lower sensitivity for minor AEs. This study aimed to assess the accuracy of the GTT for identifying AEs in adult inpatients for all AEs and for the subgroup of AEs with greater harm to the patient, classified as F-I on the IHI-GTT adapted version of the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) Index for Categorizing Errors.

METHODS: In this diagnostic test study, GTT is the index test and identification of AEs (yes/no) represents the condition of interest. Due to the lack of a gold standard test, a composite reference standard method (RSM) was developed. RSM combined real-time (during hospitalizations) and retrospective search of medical records and administrative data for screening criteria and AEs. Both tests were applied to a random sample of 211 hospitalizations of adult inpatients during Oct/Nov 2016 in a large public hospital in Belo Horizonte, Brazil. The accuracy of the GTT was evaluated using sensitivity, specificity and global accuracy.

RESULTS: A total of 176 AEs were identified in 67 admissions using RSM and 129 AEs in 76 admissions using GTT, resulting in rates of 126 and 93 AEs/1,000 patient-days, respectively. Sensitivity, specificity and global accuracy of the GTT for identification of individual AEs were, respectively, 0.41 (95% confidence interval [CI] 0.34;0.49), 0.68 (95%CI 0, 60;0.74) and 0.54 (95%CI 0.49;0.60) for all AEs, regardless of the harm categorization, and 0.85 (95%CI 0.72;0.93), 0.88 (95%CI 0.82;0.92) and 0.87 (95%CI 0.82;0.91) for the subgroup of AEs categorized as harm F-I. Among the main AEs missed by the GTT are AEs related to nursing care, such as those related to peripheral venous access and gastric/enteric catheters.

CONCLUSION: GTT proved to be a valid method for identifying AEs in adult inpatients. Its accuracy increases when minor harm AEs are not counted. Among the main adverse events missed by the GTT are those related to nursing care. Therefore, the GTT should be used in conjunction with other measurement strategies to achieve results that are representative of the quality profile of the care provided and, thus, guide the best improvement strategies.