Table 2.

Tools for the assessment of delirium

Tool	Description	Reference
CAM	Most widely used screening test for the presence of delirium; a four-item instrument based on DSM-III-R delirium criteria, requires the presence of acute onset and fluctuating course, inattention, and disorganized thinking or loss of consciousness	Inouye et al. (1990)52 Wei et al. (2008)53
CAM–ICU	Delirium is diagnosed when patients demonstrate an acute change in mental status or fluctuating changes in mental status, inattention measured with either an auditory or a visual test, and either disorganized thinking or an altered level of consciousness. Importantly, the CAM–ICU can only be administered if the patient is arousable in response to a voice without the need for physical stimulation	Ely et al. (2001)113 Ely et al. (2001)114
Drs-R98	16-item scale, including 13 severity items and 3 diagnostic items. Severity scores range from 0 to 39, with higher scores indicating more-severe delirium; delirium typically involves scores ≥15 points	Trzepacz et al. (2001)115
DSI	A structured interview detects the presence or absence of seven DSM-III criteria for delirium; delirium is said to be present if disorientation, perceptual disturbance or disturbance of consciousness have presented within the past 24h	Albert et al. (1992)116
MDAS	Measures delirium severity on a 10-item, four-point observer-rated scale with scores that range from 0 to 30	Breitbart et al. (1997)54
NEECHAM Confusion Scale	Nine scaled items divided into three subscales: subscale I, information processing (score range 0–14 points), evaluates components of cognitive status; subscale II, behavior (score range 0–10 points), evaluates observed behavior and performance ability; subscale III, performance (score range 0–16 points), assesses vital function (that is, vital signs, oxygen saturation level and urinary incontinence). Total scores can range from 0 (minimal function) to 30 (normal function). Delirium is present if the score is ≤ 24 points	Neelon et al. (1996)117
ICDSC	Bedside screening tool for delirium in the intensive care unit setting; eight-item checklist based on DSM-IV® criteria, items scored as 1 (present) or 0 (absent); a score ≥ 4 points indicates delirium	Bergeron et al. (2001)118
Cognitive Test for Delirium	Can be used with patients unable to speak or write; assesses orientation, attention, memory, comprehension and vigilance, primarily with visual and auditory modalities. Each individual domain is scored 0–6 in two-point increments, except for comprehension, which is scored in single-point increments. Total scores range from 0 to 30, with higher scores indicating better cognitive function	Hart et al. (1997)119 Hart et al. (1996)120

Abbreviations: CAM, Confusion Assessment Method; CAM–ICU, Confusion Assessment Method–Intensive Care Unit; Drs-r98, Delirium Rating Scale; DSI, Delirium Symptom Interview; DSM, Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, Arlington, VA); ICDSC, Intensive Care Delirium Screening Checklist; MDAS, Memorial Delirium Assessment Scale.