Diagnostic accuracy of the "4AT" delirium screening tool for the postoperative cardiac surgery ward

Yue Chang, Sandra M Ragheb, Nebojsa Oravec, David Kent, Kristina Nugent, Alexandra Cornick, Brett Hiebert, James L Rudolph, Alasdair M J MacLullich, Rakesh C Arora

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Background: Delirium is prevalent and under-detected among cardiac surgery patients on the postoperative ward. This study aimed to validate the 4AT delirium screening tool and evaluate its accuracy both when used by research assistants and when subsequently implemented by nursing staff on the ward.

Methods: This single centre, prospective observational study evaluated the performance of the 4AT administered by research assistants (phase one), and nursing staff (phase two). Assessments were undertaken during the patients’ first three postoperative days on the post-cardiac surgery ward along with previous routine nurse-led Confusion Assessment Method (CAM) assessments. These index tests were compared to a reference standard diagnosis of delirium based on DSM-5 criteria. Surveys regarding delirium screening were administered to nurses pre- and post-implementation of the 4AT in phase two of the study.

Results: In phase one, a total of 137 patients were enrolled, of which 24.8% experienced delirium on the postoperative cardiac ward. The 4AT had a sensitivity of 85% (95% Confidence Interval, 73%-93%) and a specificity of 90% (95% CI, 85%-93%) as compared to the reference standard. The nurse assessed CAM had a sensitivity of 23% (95% CI, 13%-37%) and specificity of 100% (95% CI, 99%-100%).

In phase two, nurses (n=51) screened 179 patients for delirium using 4AT. Compared to the reference rater, 4AT had a sensitivity of 58% (95%CI, 28%-85%) and specificity of 94% (95%CI, 85%-98%). Post-implementation, 64% of nurses felt that the 4AT improved their confidence in delirium detection, and 76% of nurses would consider routine 4AT use.

Conclusion: The 4AT demonstrated moderate sensitivity and high specificity to detect delirium in a real-world setting following cardiac surgery on the postoperative ward. A modified model of use with less frequent administration, along with increased engagement of the postoperative team, is recommended to improve early delirium detection on the cardiac surgery postoperative ward.

Original languageEnglish
JournalThe Journal of Thoracic and Cardiovascular Surgery
Publication statusPublished - 31 May 2021


Dive into the research topics of 'Diagnostic accuracy of the "4AT" delirium screening tool for the postoperative cardiac surgery ward'. Together they form a unique fingerprint.

Cite this