Confusion Assessment Method
The diagnosis of delirium requires the presence of features 1 and 2, plus either of 3 or 4.
Feature 1: Acute Onset and Fluctuation Course
This features is usually obtained from the comments by a family member or health care professionaland is shown by positive responses to the following questions:
- Is there evidence of an acute change in the mental status from the patient's baseline?
- Does the (abnormal) behavior fluctuate during the day; that is, does it tend to come and go, or increase and decrease in severity?
Feature 2: Inattention
This feature is shown by a positive resposne to the following question:
- Does the patient have difficulty focusing attention; for example, is the patient easily distractible, orhaving difficulty keeping track of what is being said?
Feature 3: Disorganized Thinking
This feature is demonstrated by a positive response to the following question:
- Is the patient's thinking disorganized or incoherent, as evidence by rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject?
Feature 4: Altered Level of Consciousness
This feature is shown by one answer other than alert to the following question:
- Overall, how would you rate the patient's level of consciousness?
- Alert (normal)
- Vigilant (hyperalert)
- Lethargic (drowsy, easily roused)
- Stuperous (drowsy, difficult to arouse)
- Comatose (unarousable)