Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2019 Jul 24;17(1):138.
doi: 10.1186/s12916-019-1367-9.

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

Susan D Shenkin  1 , Christopher Fox  2 , Mary Godfrey  3 , Najma Siddiqi  4 , Steve Goodacre  5 , John Young  6 , Atul Anand  7 , Alasdair Gray  8 , Janet Hanley  9 , Allan MacRaild  8 , Jill Steven  8 , Polly L Black  8 , Zoë Tieges  1 , Julia Boyd  10 , Jacqueline Stephen  10 , Christopher J Weir  10 , Alasdair M J MacLullich  11
Affiliations
Randomized Controlled Trial

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

Susan D Shenkin et al. BMC Med. .

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.

Trial registration: International standard randomised controlled trial number (ISRCTN) 53388093 . Date applied 30/05/2014; date assigned 02/06/2014.

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

PubMed Disclaimer

Conflict of interest statement

AMJM led the design of the 4AT in 2011 (with others, see www.the4AT.com); note that 4AT is free to download and use. SDS and AA provided comments on its development. SG is chair of the NIHR HTA Clinical Evaluation and Trials Board and member of the NIHR HTA Funding Board Policy Group. The other authors declare no competing interests.

Figures

Fig. 1
Fig. 1
The 4 ‘A’s Test (4AT)
Fig. 2
Fig. 2
Diagnostic accuracy study: overview flowchart. ED, Emergency Department; MOE, Medicine of the Elderly; 4AT, 4 ‘A’s Test; CAM, Confusion Assessment Method
Fig. 3
Fig. 3
STARD diagram of the flow of participants through the study (total across all three sites)
Fig. 4
Fig. 4
Receiver operator characteristic curve for 4AT diagnostic accuracy. 4AT scores range from 0 to 12. The cut-point of > 3 is used in the scoring scheme to denote likely delirium. The 4AT scores are considered against the reference standard delirium assessment
See this image and copyright information in PMC

References

    1. Reynish EL, Hapca SM, De Souza N, Cvoro V, Donnan PT, Guthrie B. Epidemiology and outcomes of people with dementia, delirium, and unspecified cognitive impairment in the general hospital: prospective cohort study of 10,014 admissions. BMC Med. 2017;15(1):140. doi: 10.1186/s12916-017-0899-0. - DOI - PMC - PubMed
    1. Pendlebury ST, Lovett NG, Smith SC, Dutta N, Bendon C, Lloyd-Lavery A, Mehta Z, Rothwell PM. Observational, longitudinal study of delirium in consecutive unselected acute medical admissions: age-specific rates and associated factors, mortality and re-admission. BMJ open. 2015;5(11):e007808. doi: 10.1136/bmjopen-2015-007808. - DOI - PMC - PubMed
    1. Marcantonio ER. Delirium in hospitalised older adults. N Engl J Med. 2017;377(15):1456–1466. doi: 10.1056/NEJMcp1605501. - DOI - PMC - PubMed
    1. Oh ES, Fong TG, Hshieh TT, Inouye SK. Delirium in older persons: advances in diagnosis and treatment. JAMA. 2017;318(12):1161–1174. doi: 10.1001/jama.2017.12067. - DOI - PMC - PubMed
    1. Goldberg SE, Whittamore KH, Harwood RH, Bradshaw LE, Gladman JR, Jones RG. The prevalence of mental health problems among older adults admitted as an emergency to a general hospital. Age Ageing. 2012;41(1):80–86. doi: 10.1093/ageing/afr106. - DOI - PMC - PubMed

Publication types

MeSH terms

Associated data