Objective assessment of attention in delirium: a narrative review.
OBJECTIVE
Inattention is a core feature of delirium, and valid assessment of attention is central to diagnosis. Methods of measuring attention in delirium can be divided into two broad categories: (i) objective neuropsychological testing; and (ii) subjective grading of behaviour during interview and clinical examination. Here, we review and critically evaluate studies of objective neuropsychological testing of attention in delirium. We examine the implications of these studies for delirium detection and monitoring in clinical practice and research, and how these studies inform understanding of the nature of attentional deficits in delirium.


METHODS
Searches of MEDLINE and ISI Web of Knowledge databases were performed to identify studies in which objective tests of attention had been administered to patients with delirium, who had been diagnosed using DSM or ICD criteria.


RESULTS
Sixteen publications were identified. The attention tests administered in these studies were grouped into the following categories: measures of attention span, vigilance tests, other pen-and-paper tests (e.g. Trail Making Test) and computerised tests of speeded reaction, vigilance and sustained attention. Patients with delirium showed deficits on all tasks, although most tasks were not considered pure measures of attention. Five papers provided data on differential diagnosis from dementia. Cancellation tests, spatial span tests and computerised tests of sustained attention discriminated delirium from dementia. Five studies presented reliability or validity statistics.


CONCLUSIONS
The existing evidence base on objective assessment of attention in delirium is small. Objective testing of attention is underdeveloped but shows considerable promise in clinical practice and research.
Edinburgh Delirium Research Group, Geriatric Medicine, Division of Health Sciences, School of Clinical Sciences, University of Edinburgh, Edinburgh, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, UK.
Zoë
Z
Tieges
Laura J E
LJ
Brown
Alasdair M J
AM
MacLullich
D001288:Attention; D003693:Delirium / Q000175:diagnosis* / Q000523:psychology; D003704:Dementia / Q000175:diagnosis / Q000523:psychology; D006801:Humans; D009483:Neuropsychological Tests / Q000592:standards*; D015203:Reproducibility of Results; D013647:Task Performance and Analysis
attention; cognitive tests; delirium; dementia; objective assessment; review