The Confusion Assessment Method (CAM) is a widely used diagnostic tool for identifying delirium. It was developed by researchers at the Yale University School of Medicine and has become the gold standard for diagnosing delirium in clinical settings. The CAM helps healthcare professionals systematically evaluate and identify the presence of delirium based on four key features.
Confusion Assessment Method (CAM) for Diagnosing Delirium*
| Feature | Assessment |
| Required features | |
| Acute onset and fluctuating course | Shown by positive responses to the following questions: “Has the patient’s mental status changed abruptly from baseline?” “Did the abnormal behavior fluctuate during the day (ie, tend to come and go or increase and decrease in severity)?” |
| Inattention | Shown by a positive response to the following question: “Did the patient have difficulty focusing attention (eg, was easily distracted or had difficulty following what was being said)?” |
| One of the following features required | |
| Disorganized thinking | Shown by a positive response to the following question: “Was the patient’s thinking disorganized or incoherent (eg, evidenced by rambling or irrelevant conversation, unclear or illogical flow of ideas, or unpredictable switching from subject to subject)?” |
| Altered level of consciousness | Shown by any answer other than “alert” to the following question: “Overall, how would you rate this patient’s level of consciousness?”
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* The diagnosis of delirium requires the presence of the first 2 features plus one of the second 2 features.
References:
- Wei LA, Fearing MA, Sternberg EJ, Inouye SK. The Confusion Assessment Method: a systematic review of current usage. J Am Geriatr Soc. 2008 May;56(5):823-30. [Medline]
- Shenkin SD, Fox C, Godfrey M, Siddiqi N, Goodacre S, Young J, Anand A, Gray A, Hanley J, MacRaild A, Steven J, Black PL, Tieges Z, Boyd J, Stephen J, Weir CJ, MacLullich AMJ. Delirium detection in older acute medical inpatients: a multicentre prospective comparative diagnostic test accuracy study of the 4AT and the confusion assessment method. BMC Med. 2019 Jul 24;17(1):138. [Medline]
Created Jul 13, 2023.
