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Confusion Assessment Method

Confusion Assessment Method (CAM) was originally developed in 1988 to improve the identification and recognition of delirium. The CAM was intended to provide a new standardized method to enable non-psychiatrically trained clinicians to identify delirium quickly and accurately in both clinical and research settings. Since its development, the CAM has become the most widely used delirium detection instrument world-wide, due to its strong validation results as well as its ease of use.


The CAM instrument has been used in over 5,000 original articles to date, as either a process or outcome measure, and has been translated into over 14 languages.

Dr. Sharon Inouye and colleagues have developed a series of CAM-related instruments for the recognition and diagnosis of delirium. The instruments and their training manuals are available for free after a brief one-time registration.

  • Confusion Assessment Method (Short CAM)This 4-item tool is the most widely used tool worldwide for recognition of delirium for both clinical and research purposes.                           

Reference: Inouye SK, VanDyck CH, Alessi CA et al. Clarifying confusion: The Confusion Assessment Method. A new method for detecting delirium. Ann Intern Med. 1990; 113:941-8.

  • Confusion Assessment Method (Long CAM)This 10-item tool is the gold standard for delirium identification, and is strongly recommended for all research uses.

Reference: Inouye SK, VanDyck CH, Alessi CA et al. Clarifying confusion: The Confusion Assessment Method. A new method for detecting delirium. Ann Intern Med. 1990; 113:941-8.

  • CAM-S (for measuring delirium severity)The CAM-S is a tool for measuring delirium severity with either the short or long version of the CAM.

Reference: Inouye SK, Kosar CM, Tommet D, Schmitt EM, Puelle MR, Saczynski JS, Marcantonio ER, Jones RN. The CAM-S: Development and Validation of a New Scoring System for Delirium Severity in 2 Cohorts. Ann Intern Med. 2014; 160:526-533

  • FAM-CAM (family assessment of delirium)The FAM-CAM is designed to be used with family caregivers to enhance the recognition of delirium.

Reference: Steis MR, Evans L, Hirschman KB, Hanlon A, Fick DM, Flanagan N, Inouye SK. Screening for Delirium via Family Caregivers: Convergent Validity of the Family Confusion Assessment Method (FAM-CAM) and Interviewer-Rated CAM. J Am Geriatr Soc. 2012; 60:2121-26. PMC3498543

  • 3D-CAM (brief cognitive screen with CAM)The 3D-CAM is a three minute assessment tool that can be used to test patients for delirium in both clinical and research settings.

Reference: *Marcantonio ER, Ngo L, O’Connor MA, Jones RN, Crane PK, Metzger ED, Inouye SK. 3DCAM: Validation of a 3-Minute Diagnostic Interview for CAM-defined Delirium. Ann Int Med. 2014; 161(8):554-561.

  • CHART-DEL (Chart Delirium Identification): The CHART-DEL is a validated method that can be used to review charts (medical records) to detect the presence of delirium.

Reference: Inouye SK, Leo-Summers L, Zhang Y, Bogardus ST, Leslie DL, Agostini JV. A chart-based method for identification of delirium: validation compared with interviewer ratings using the Confusion Assessment Method. J Am Geriatr Soc. 2005:53:312-318 

Reference: Saczynski JS, Kosar CM, Xu G, Puelle MR, Schmitt E, Jones RN, Marcantonio ER, Wong B, Isaza I, Inouye SK. A Tale of Two Methods: Chart and Interview Methods for Identifying Delirium. J Am Geriatr Soc. 2014; 62:518-524. PMC3959564

  • DEL-B-C and DEL-B-P: The Delirium Burden instruments are designed to be used as a means of quantifying the burden of an acute delirium episode (lasting hours to days). Burden refers to the distress that patients and caregivers may feel in response to symptoms and stressful situations surrounding the episode.

Reference: Racine AM, D'Aquila M, Schmitt EM, Gallagher J, Marcantonio ER, Jones RN, Inouye SK, Schulman-Green D; BASIL Study Group. Delirium Burden in Patients and Family Caregivers: Development and Testing of New Instruments. Gerontologist. 2019 Sep 17;59(5):e393-e402. doi: 10.1093/geront/gny041.