COMBI >> Scales >> CAP >> Syllabus


Mark Sherer, PhD, ABPP-Cn, The Institute for Rehabilitation Research at

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Sherer, M. (2004). The Confusion Assessment Protocol. The Center for Outcome Measurement in Brain Injury.
combi/cap ( accessed ).





CAP Syllabus

CAP Administration

Print out a copy of the CAP to refer to as you review these instructions. The sources for CAP items are indicated on the protocol. Complete references are cited in the Reference section.

As with any other neuropsychological test, the examiner should develop some rapport prior to starting administration. The patient should be examined in a quiet room as free of distractions as possible. Some confused patients can only tolerate very brief testing sessions. For such patients it is acceptable to break up administration into more than one session on the same day. The CAP can be administered as part of a longer, comprehensive bedside assessment. For the typical patient, CAP examination requires less than 30 minutes. Some parts of the CAP have alternative forms (CTD Vigilance, CTD Visual Picture Memory Test, CTD Comprehension Test). These forms should be alternated on successive administrations of the CAP.

Failure to respond on any CAP item is given the lowest possible score. If the patient discontinues or avoids items due to agitation or drowsiness, the lowest possible score is given. Test completion codes are provided on the protocol to allow the examiner to indicate whether each item was completed in a standard administration or could not be completed due to decreased level of arousal, motor impairment, visual impairment, inability to phonate, aphasia, or agitation.

TOTART Attentional Subtest: Items are read to the patient as indicated on the protocol. Cuing (20, 19, 18) is permitted for the counting backwards item. No other cuing is permitted. Items are scored as correct or incorrect; there is no partial credit. When cued for counting backwards, the patient may pick up with 17 and count down to 1 and still be scored correct. Some patients may repeat their responses which may indicate perseveration. For example the patient may count to 20 and then start counting to 20 again. The first time this happens, the patient should be instructed to perform each task only once. Subsequent repetitions are scored as errors.

CTD Vigilance: After reading the instructions, the set of letters is read to the patient. The patient can indicate that he/she has heard the letter H in any manner (raised hand, head nod, the word “yes”, etc.) as long as the indication is clear to the examiner. The number of hits (correctly identified targets is calculated and multiplied by 2. Next the number of commissions (incorrectly identified targets, that is letters other than H that are responded to) is calculated. The Vigilance score is calculated by subtracting the number of commissions from the number of hits multiplied by 2. Thus the score is (hits X 2) – commissions.

GOAT: The GOAT is administered in the standard manner. See Levin, O’Donnell, and Grossman (1979) for additional information.

CTD Visual Picture Memory Test: Pictures of 5 common objects are shown to the patient. Each picture is displayed for 3 seconds. The CTD Comprehension Test is administered to create a brief delay. Next, pictures of 10 objects are shown to the patient. This set of 10 pictures includes the 5 previously displayed pictures and 5 novel pictures. The patient is asked to indicate which pictures he/she has seen before. The patient may indicate in any manner. One point is given for each correct recognition of a previously displayed picture (a yes response) and each correct recognition of a novel picture (a no response). The highest possible score is 10.

The picture stimuli are provided in the original CTD paper by Hart and colleagues (1996). We created our stimuli by enlarging the stimuli from the article. Pictures were then individually cut-out and laminated. Note that 2 copies of the 2 sets of 5 target pictures are needed. This allows the examiner to have a set of 5 pictures to be displayed and then a separate set of 10 pictures (5 targets and 5 novel pictures) for the recognition trial.

CTD Comprehension Test: As indicated in the instructions on the protocol, the 4 questions are read to the patient. The patient may answer yes or no in any manner (head nods/shakes, the word yes/no, thumbs up/down, etc.) as long as the indication is clear to the examiner. Some patients may attempt to discuss the question rather than giving a yes/no response. The examiner should firmly insist on a yes or no response.

ABS: The ABS is administered as described by Corrigan (1989). For CAP scoring, ABS ratings should be based on the direct observations of the examiner as well as the input from nursing staff and therapists who have worked with the patient in the 8 hour period during which the CAP was administered. For examiners who do not have previous ABS rating experience, we find it helpful to have a more experienced examiner co-rate some patients initially to help the novel examiner learn a standard way of rating the scale.

Clinician Rated Items: The fluctuation, perceptual disturbances and hallucinations, delusions, and thought process abnormalities items were taken from the DRS-R. The DRS-R sleep-disturbance item is rated based on both nighttime and daytime sleep disturbance. Based on our clinical experience, we thought that it was important to separate nighttime and daytime sleep disturbance. The DRS-R sleep-disturbance item was modified so that it is just rated based on nighttime sleep pattern. We recommend that nighttime sleep graphs are completed by nursing staff to assist with rating this item. A new item was created to capture decreased daytime level of arousal. For each of the Clinician Rated Items, as with the ABS, the examiner should rate the item based on direct observations as well as input from nursing staff and therapists who have worked with the patient in the 8 hour period during which the CAP was administered.


CAP Scoring

Scores are calculated on the final page of the protocol. Correct performances on TOTART items are given various point values based on the difficulty of the items. All incorrect performances are scored 0. Point values are assigned to CTD Vigilance scores. Recall that the CTD Vigilance score = (hits X 2) – commissions. CTD Comprehension and CTD Recognition scores are assigned points in a similar manner. The cognitive points are totaled (the maximum point total is 28). Totals < 18 indicate cognitive impairment of sufficient severity to possibly indicate confusion and such a total would count as one symptom of confusion. If the cognitive total is < 18, a 1 should be put in the far right column by Cognitive Impairment.

Disorientation is determined by the GOAT. A GOAT error score > 24 (indicating a GOAT score < 76) indicates disorientation and a 1 should be put in the far right column by Disorientation.

Agitation (restlessness) is assessed with the ABS. Scores > 17 indicate significant restlessness and a 1 should be put in the far right column by Agitation.

Fluctuation of Symptoms is assessed with the first clinician rated item. A rating of 1 or 2 on that item indicates significant fluctuation and a 1 should be put in the far right column by Fluctuation.

Sleep Disturbance is assessed with the second clinician rated item. Scores of 2 or 3 indicate significant sleep disturbance and a 1 should be put in the far right column by Sleep Disturbance.

Decreased Daytime Arousal is assessed with the third clinician rated item. Scores of 2 or 3 indicate significantly decreased daytime arousal and a 1 should be put in the far right column by Decreased Daytime Arousal.

Psychotic-type Symptoms are assessed with clinician rated items 4, 5, and 6. Scores of 1, 2, or 3 on item 4 (Perceptual Disturbances and Hallucinations) or scores of 1, 2, or 3 on item 5 (Delusions) or scores of 2 or 3 on item 6 (Thought Process Abnormalities) are indications of psychotic-type symptoms and a 1 should be put in the far right column by Psychotic-type Symptoms.

Once scores of 1 or 0 are assigned for each of the 7 symptoms of confusion, these scores are summed. CAP totals of 4 or higher indicate that the patient is in PCS. CAP totals of 3 indicate that the patient is in PCS if one of the 3 symptoms present is disorientation.


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