CAM: Confusion Assessment Method
1990CAM is a feature-based method applied to information gathered through interview, cognitive assessment, observation and history. It supports assessment for current delirium.
Classification
A tool may belong to more than one category. Select a linked category to see other relevant profiles.
Tool and original sources
Copyright restrictions mean that a copy of the CAM cannot be provided on this website. Official versions are available from Delirium Central. Google Images may also help you see what the form looks like.
Original and selected diagnostic-accuracy papers
- Original paperInouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Annals of internal medicine. 1990;113(12):941-8. doi: 10.7326/0003-4819-113-12-941. PMID: 2240918.
This is the original published source for CAM. It is the main source for the method, its intended use and the evidence available at publication.
- Systematic review of diagnostic accuracyWei LA, Fearing MA, Sternberg EJ, Inouye SK. The Confusion Assessment Method: a systematic review of current usage. Journal of the American Geriatrics Society. 2008;56(5):823-30. doi: 10.1111/j.1532-5415.2008.01674.x. PMID: 18384586.
This systematic review synthesised diagnostic-accuracy evidence for CAM. Across 7 studies involving 1,071 participants in the pooled high-quality validation studies, pooled sensitivity was 94% and specificity was 89%.
- Systematic review of diagnostic accuracyWong CL, Holroyd-Leduc J, Simel DL, Straus SE. Does this patient have delirium?: value of bedside instruments. JAMA. 2010;304(7):779-86. doi: 10.1001/jama.2010.1182. PMID: 20716741.
This systematic review synthesised diagnostic-accuracy evidence for CAM. Systematic diagnostic-accuracy review; the CAM had the strongest supportive bedside evidence, with summary LR+ 9.6 and LR- 0.16.
At a glance
- Purpose
- Episodic assessment
- Population
- Adult
- Setting
- General / acute hospital
- Time
- CAM feature rating can be brief; total time depends on the interview, cognitive assessment, observation and history used to gather the features
- Items
- 4
- Score or threshold
- Feature-based CAM classification; see the authorised materials for the decision rule.
Format: A clinician rating completed after an interview and brief cognitive assessment. The short form records four clinical feature ratings; the longer worksheet supports a broader assessment. Prompts, feature wording and the final decision rule are not reproduced here.
- Strengths: Extensively studied feature-based assessment; basis of several related tools
- Limitations: Performance depends on training and on the quality of the assessment used to rate its features
Evidence
Reported sensitivity and specificity
Two sites, n=56; against psychiatrist diagnosis.
More evidence and citation details
- Full name
- Confusion Assessment Method
- Training
- Use the current CAM manual and recommended training. Performance depends on the interview, cognitive assessment, observation and history used to gather the feature ratings.
- Evidence summary
- pooled
- Diagnostic-accuracy studies
- 36
- Reference standard
- DSM-III-R (psychiatrist)
- Reliability
- Inter-rater κ 0.81–1.0
- Real-world use
- Completion varied widely (up to 99% in dedicated programmes, lower elsewhere); admission positive-score rates were 8–51% and inpatient rates 2–20%. Low rates may reflect case mix, timing, selective completion or under-detection and should prompt local audit rather than a single conclusion. (Penfold 2024)
- Citation
- Inouye SK, van Dyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI Clarifying confusion: the confusion assessment method. A new method for detection of delirium Annals of internal medicine. 1990;113(12):941-8. PMID 2240918
Copyright and reuse
- Version
- Use the current Short or Long CAM supplied by the author-led resource page
- Rights holder
- Hospital Elder Life Program (copyright); Aging Brain Center (permissions administrator)
- Licence
- ALL-RIGHTS-RESERVED-PERMISSION-REQUIRED
- Information checked
- 2026-07-19
Instrument-specific terms apply. See the access and copyright policy or send a correction.
Sources checked 2026-07-29. How profiles are prepared.