Short CAM: Short-form Confusion Assessment Method

1990

The four-feature short CAM is what people usually mean when they say “the CAM”. It uses the diagnostic algorithm from the original 1990 study. Its ratings follow an interview with cognitive testing, observation and history.

At a glance

Purpose: Episodic assessment
Population: Adult
Setting: General / acute hospital
Time: ~5-10 min including the supporting interview or cognitive assessment
Diagnostic features: 4; supporting cognitive assessment is also required
Score or threshold: Feature-based Short CAM classification; see the authorised materials.

Format: Four clinical feature ratings cover acute onset or fluctuation, inattention, disorganised thinking and altered level of consciousness. They are not four patient questions. Complete the supporting interview and cognitive assessment before rating them. The long CAM adds six symptom ratings while retaining the same diagnostic algorithm.

Short CAM and long CAM

Short CAM: the four-feature diagnostic form usually meant by “the CAM”. Its algorithm comes from the original 1990 study. The features are clinical ratings made after an interview with cognitive testing.

Long CAM: the broader ten-item form. It adds ratings of disorientation, memory, perception, activity and the sleep–wake cycle. It retains the same diagnostic algorithm.

The long CAM: what it adds to the short form →

The original paper described nine criteria; four contributed to the diagnostic algorithm. The current long form rates agitation and slowing separately. Original paper · Current forms and guidance

Training and instructions

Instrument-specific manual. Public developer resource page. Choose the exact instrument and version.
Short CAM training manual. Short CAM diagnostic training manual, revised January 2020. It also includes short-form CAM-S severity instructions. The filename alone does not identify the purpose.
Short CAM form and manual. The four-feature diagnostic form, supporting cognitive assessment and scoring instructions. This is distinct from CAM-S severity scoring.
Long CAM form, manual and training videos. The broader ten-item CAM form. The page also links training videos and answer keys.

Start here

Tool and original sources

Copyright restrictions mean that a copy of the Short CAM cannot be provided on this website. Official materials are available from Delirium Central. Google Images may also help you see what the form looks like.

Open the official tool page ↗ Search Google Images ↗

Original and selected diagnostic-accuracy papers

Principal sourceInouye 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 principal published source for Short CAM. It is the main source for the method, its intended use and the evidence available at publication.
Open PubMed ↗
Selected diagnostic-accuracy studyHeinrich TW, Kato H, Emanuel C, Denson S. Improving the Validity of Nurse-Based Delirium Screening: A Head-to-Head Comparison of Nursing Delirium-Screening Scale and Short Confusion Assessment Method. Psychosomatics. 2019;60(2):172-178. doi: 10.1016/j.psym.2018.09.002. PMID: 31416628.
This diagnostic-accuracy study evaluated Short CAM in general medical hospital units against a DSM-5 clinical assessment. It reported sensitivity of 8.6% and specificity of 100% in 192 general medical inpatients; 35 delirium cases.
Open PubMed ↗

One DTA study identifiedVersion or adaptation

Classification

Episodic assessment

A tool may belong to more than one category. Select a linked category to see other relevant profiles.

Evidence

Diagnostic-accuracy evidenceOne DTA study identified

Reported sensitivity and specificity

Headline metric source

Later validation or evaluation · 2019; pmid:31416628

Denominator: Reported source unit: 192 (analysis unit not fully reconciled)
Reference standard: Two blinded physician DSM-5 delirium assessments

8.6%

Sensitivity

100%

Specificity

Earliest DTA evaluation identified in the current audit; see the linked source and methodological caveats.

More evidence and citation details

Full name: Short-form Confusion Assessment Method
Also known as: Short-CAM, short form CAM
Related profiles: CAM
Evidence summary: pooled-family-evidence
Diagnostic-accuracy evaluations: 1
Reference standard: Two blinded physician DSM-5 delirium assessments
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):941-948. PMID 2240918

Download RIS ↗ Download BibTeX ↗

Primary validation studies

Distinct primary publications from the current diagnostic-accuracy audit. Reviews and repeated evaluations within one paper are not counted again. Overlapping cohorts have not all been reconciled. Read the counting rules and limitations.

Open 1 identified paper

Heinrich TW, Kato H, Emanuel C, Denson S (2019). Improving the Validity of Nurse-Based Delirium Screening: A Head-to-Head Comparison of Nursing Delirium-Screening Scale and Short Confusion Assessment Method. Psychosomatics.
Reference category: independent clinical reference.

Version: Use the current Short 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.

Base clinical review: 2026-09-05. Instrument description source check: 2026-09-05. Scope and limitations.