Basic Study
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World J Psychiatr. Apr 19, 2020; 10(4): 46-58
Published online Apr 19, 2020. doi: 10.5498/wjp.v10.i4.46
Comparison of novel tools with traditional cognitive tests in detecting delirium in elderly medical patients
David J Meagher, Henry O’Connell, Maeve Leonard, Olugbenga Williams, Fahad Awan, Chris Exton, Michael Tenorio, Margaret O’Connor, Colum P Dunne, Walter Cullen, John McFarland, Dimitrios Adamis
David J Meagher, Henry O’Connell, Maeve Leonard, Olugbenga Williams, Fahad Awan, Margaret O’Connor, Colum P Dunne, Walter Cullen, John McFarland, Dimitrios Adamis, Cognitive Impairment Research Group, Graduate Entry Medical School, University of Limerick, Limerick V94 YVHO, Ireland
Chris Exton, Michael Tenorio, Department of Computer Sciences, University of Limerick, Limerick V94 YVHO, Ireland
Walter Cullen, School of Medicine, University College Dublin, Dublin 4 D04 V1W8, Ireland
Dimitrios Adamis, Sligo Mental Health Services, Ballytivan, Sligo F91 CD34, Ireland
Author contributions: Meagher DJ, O’Connell H, Leonard M, Williams O, Awan F, Exton C, Tenorio M, O’Connor M, Dunne CP, Cullen W, McFarland J and Adamis D contributed to the writing and revising of the manuscript; all authors approved the final version of the manuscript.
Institutional review board statement: The study was reviewed and approved by University Hospital Limerick Regional Ethics Committee approved (REC 100/12).
Conflict-of-interest statement: The authors have no conflicts of interest to declare other than that they are members of the Cognitive Impairment Research Group (CIRG) that developed the Lighthouse and LSD tests described in this study.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: David J Meagher, MD, PhD, Chairman, Professor, Head, Department of Psychiatry, Graduate Entry Medical School, University of Limerick, Limerick V94 YVHO, Ireland. david.meagher@ul.ie
Received: October 2, 2019
Peer-review started: October 2, 2019
First decision: November 6, 2019
Revised: January 17, 2020
Accepted: March 4, 2020
Article in press: March 4, 2020
Published online: April 19, 2020
Processing time: 197 Days and 21.9 Hours
Abstract
BACKGROUND

Efficient detection of delirium and comorbid delirium-dementia is a key diagnostic challenge. Development of new, efficient delirium-focused methods of cognitive assessment is a key challenge for improved detection of neurocognitive disorders in everyday clinical practice.

AIM

To compare the accuracy of two novel bedside tests of attention, vigilance and visuospatial function with conventional bedside cognitive tests in identifying delirium in older hospitalized patients.

METHODS

180 consecutive elderly medical inpatients (mean age 79.6 ± 7.2; 51% female) referred to a psychiatry for later life consultation-liaison service with delirium, dementia, comorbid delirium–dementia and cognitively intact controls. Participants were assessed cross-sectionally with conventional bedside cognitive tests [WORLD, Months Backward test (MBT), Spatial span, Vigilance A and B, Clock Drawing test and Interlocking Pentagons test] and two novel cognitive tests [Lighthouse test, Letter and Shape Drawing test (LSD)-4].

RESULTS

Neurocognitive diagnoses were delirium (n = 44), dementia (n = 30), comorbid delirium-dementia (n = 60) and no neurocognitive disorder (n = 46). All conventional tests had sensitivity of > 70% for delirium, with best overall accuracy for the Vigilance-B (78.3%), Vigilance-A (77.8%) and MBT (76.7%) tests. The sustained attention component of the Lighthouse test was the most distinguishing of delirium (sensitivity 84.6%; overall accuracy 75.6%). The LSD-4 had sensitivity of 74.0% and overall accuracy 74.4% for delirium identification. Combining tests allowed for enhanced sensitivity (> 90%) and overall accuracy (≥ 75%) with the highest overall accuracy for the combination of MBT-Vigilance A and the combined Vigilance A and B tests (both 78.3%). When analyses were repeated for those with dementia, there were similar findings with the MBT-Vigilance A the most accurate overall combination (80.0%). Combining the Lighthouse-SA with the LSD-4, a fail in either test had sensitivity for delirium of 91.4 with overall accuracy of 74.4%.

CONCLUSION

Bedside tests of attention, vigilance and visuospatial ability can help to distinguish neurocognitive disorders, including delirium, from other presentations. The Lighthouse test and the LSD-4 are novel tests with high accuracy for detecting delirium.

Keywords: Visuospatial function; Attention; Vigilance; Letter and Shape Drawing test; Lighthouse test; Delirium; Dementia; Phenomenology; Assessment

Core tip: This study examines the accuracy of a range of conventional and novel bedside cognitive tests in identifying delirium amongst older medical patients within a general hospital setting. The novel tests (Letter and Shape Drawing test, and Lighthouse test) compare favourably with conventional tests and may be particularly useful by virtue of their capacity to provide highly consistent testing in real world practice.