Table 2.

Delirium instruments for use in patients with dementia

Instrument	Description	Administration time	Informant?	Scoring	Cohort description	Delirium sensitivity/specificity	Comments	Ref.
Six Item Cognitive Impairment Test (6-CIT)	Logical memory item (recall of a 5-item address), two attention items (counting backward 20–1, and MOYB) and three orientation questions (year, month, time)	2 min	No	Values range from 0 to 28; higher scores indicate greater cognitive impairment. A 9/10 cut-off can be used for dementia	n = 419 Delirium: 15.2% Dementia: 21.5% DSD: 49.4%	Sensitivity of 90% Specificity of 63%		Brooke and Bullock25 O’Sullivan et al149
4 A’s test; Arousal, Attention, Abbreviated Mental Test - 4, Acute change (4AT)	Alertness, orientation, and attention plus family or caregiver collateral information	< 2 min	Optional	Scored from 0 to 12, with a score of 0 (with collateral information) indicating delirium or significant cognitive impairment are unlikely, scores of 1–3 suggestive of cognitive impairment and scores ≥4 indicative of delirium	n = 234 Delirium: 12% Dementia: 31% DSD: 7%	Sensitivity of 90% Specificity of 84%	Performance may be reduced in patients with dementia	Bellelli et al26
4-DSD	Level of alertness, altered brain function, attention, and acute change and fluctuations in mental status	3 min	Yes	4-item scale (range: 0–12, higher scores suggest the presence of delirium	n = 134 Dementia: 100% DSD: 80.4%	Sensitivity of 80% Specificity of 80% Note: psychometric properties of the 4-DSD varied by the severity of the cognitive impairment	Several of the items in the 4-DSD may be attributable to the underlying dementia process and not to the delirium, such as unawareness, presence of sleep–wake disorder, and inattention. Symptoms often found in both dementia and delirium are not assessed (such as agitation, aggression, or psychomotor retardation) or incorporated into the scoring	Morandi et al27
3D-CAM	Informs each of the CAM features: acute-onset or fluctuating course; and inattention and either disorganized thinking or altered level of consciousness	3 min	Yes	Delirium is present if (1) acute onset or fluctuating course, (2) inattention, and (3) either disorganized thinking or (4) altered LOC	n = 201 Delirium 21% Dementia 27% DSD 14%	Sensitivity of 95% Specificity of 94%	Key features of delirium that are identified in two ways: by asking the patient questions and by observing the patient’s speech and behavior	Marcantonio et al28
Ultra-Brief CAM (UB-CAM)	Uses the combination of “months of the year backward” and “what is the day of the week?” (UB-2)	35–40 sec for the UB-2 only, and 1 min 30 s for UB-2 + 3D-CAM with skip	Yes	If both items on UB-2 are correct, delirium is excluded. If one or more errors on UB-2, continue with the 3D-CAM with a skip pattern in a “positive” protocol	n = 527 Delirium: 27% Dementia: 35% DSD: 64%	Sensitivity of 64% Specificity of 94% (nurse rating)	Brief testing is often better tolerated in patients with dementia; patient must be verbal	Fick et al29 Fick et al150

Abbreviations: DSD, delirium superimposed on dementia; MOYB, month of the year backward.