Delirium detection in older acute medical inpatients: a multicentre prospective comparative diagnostic test accuracy study of the 4AT and the confusion assessment method

Abstract

Background

Delirium affects > 15% of hospitalised patients but is grossly underdetected, contributing to poor care. The 4 ‘A’s Test (4AT, www.the4AT.com) is a short delirium assessment tool designed for routine use without special training. The primary objective was to assess the accuracy of the 4AT for delirium detection. The secondary objective was to compare the 4AT with another commonly used delirium assessment tool, the Confusion Assessment Method (CAM).

Methods

This was a prospective diagnostic test accuracy study set in emergency departments or acute medical wards involving acute medical patients aged ≥ 70. All those without acutely life-threatening illness or coma were eligible. Patients underwent (1) reference standard delirium assessment based on DSM-IV criteria and (2) were randomised to either the index test (4AT, scores 0–12; prespecified score of > 3 considered positive) or the comparator (CAM; scored positive or negative), in a random order, using computer-generated pseudo-random numbers, stratified by study site, with block allocation. Reference standard and 4AT or CAM assessments were performed by pairs of independent raters blinded to the results of the other assessment.

Results

Eight hundred forty-three individuals were randomised: 21 withdrew, 3 lost contact, 32 indeterminate diagnosis, 2 missing outcome, and 785 were included in the analysis. Mean age was 81.4 (SD 6.4) years. 12.1% (95/785) had delirium by reference standard assessment, 14.3% (56/392) by 4AT, and 4.7% (18/384) by CAM. The 4AT had an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84–0.96). The 4AT had a sensitivity of 76% (95% CI 61–87%) and a specificity of 94% (95% CI 92–97%). The CAM had a sensitivity of 40% (95% CI 26–57%) and a specificity of 100% (95% CI 98–100%).

Conclusions

The 4AT is a short, pragmatic tool which can help improving detection rates of delirium in routine clinical care.

Metadata

Authors/Creators:

Shenkin, SD
Fox, C
Godfrey, M https://orcid.org/0000-0002-2408-534X
Siddiqi, N
Goodacre, S
Young, J
Anand, A
Gray, A
Hanley, J
MacRaild, A
Steven, J
Black, PL
Tieges, Z
Boyd, J
Stephen, J
Weir, CJ
MacLullich, AMJ

© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Keywords:

Delirium; Diagnostic test accuracy; 4AT; Confusion assessment method (CAM); Sensitivity; Specificity; Hospital

Dates:

Accepted: 13 June 2019
Published: 24 July 2019

Institution:

The University of Leeds

Academic Units:

The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Health Sciences (Leeds) > Academic Unit of Elderly Care and Rehabilitation (Leeds)

Funding Information:

Funder	Grant number
NIHR National Inst Health Research	RA2498

Depositing User:

Symplectic Publications

Date Deposited:

15 Aug 2019 09:16

Last Modified:

25 Jun 2023 21:57

Status:

Published

Identification Number:

https://doi.org/10.1186/s12916-019-1367-9

CORE (COnnecting REpositories)

Delirium detection in older acute medical inpatients: a multicentre prospective comparative diagnostic test accuracy study of the 4AT and the confusion assessment method

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