CAC-A: Clinical Assessment of Confusion-A
1990A 25-item nurse-observed measure of acute confusion across five behavioural dimensions. It has later delirium criterion-validity evidence, but its construct is broader than criterion-based delirium diagnosis.
Classification
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Tool and original sources
This record describes a method rather than a downloadable bedside form. The main source is linked below.
Original and selected diagnostic-accuracy papers
- Original paperVermeersch PE. The clinical assessment of confusion-A. Applied nursing research : ANR. 1990;3(3):128-33. doi: 10.1016/s0897-1897(05)80132-6. PMID: 2400212.
This is the original published source for CAC-A itself. It is the main source for the method, its intended use and the evidence available at publication.
- Selected diagnostic-accuracy studyPompei P, Foreman M, Cassel CK, Alessi C, Cox D. Detecting delirium among hospitalized older patients. Archives of internal medicine. 1995;155(3):301-7. doi: 10.1001/archinte.1995.00430030095011. PMID: 7832602.
This diagnostic-accuracy study evaluated CAC-A in four medical and surgical wards of a university teaching hospital against a DSM-III-R clinical assessment. It reported sensitivity of 36% and specificity of 95% in 432 hospitalised adults aged 65 years or older; 64 developed delirium.
At a glance
- Purpose
- Episodic assessment
- Population
- Adult
- Setting
- General / acute hospital
- Time
- approximately 5 min after observation
- Items
- 25
- Score or threshold
- Higher totals indicate greater confusion; later studies have used five or more abnormal behaviours for case-finding
Format: CAC-A aggregates observed behaviours across five dimensions into a total in which higher values reflect more confusion. The complete behavioural statements should be obtained from the publication or NIDUS card rather than copied into this commentary.
Evidence
Reported sensitivity and specificity
Later validation or evaluation · 1995 — pmid:7832602
- Denominator
- Reported source unit: 432 (analysis unit not fully reconciled)
- Reference standard
- One of five clinician investigators (four geriatricians, one geriatric nurse specialist) applying operationalised DSM-III-R delirium criteria within 24 hours of referral
Earliest DTA evaluation identified in the current audit; see the linked source and methodological caveats.
More evidence and citation details
- Full name
- Clinical Assessment of Confusion-A
- Also known as
- CAC-A, Clinical Assessment of Confusion A
- Related profiles
- CAC-B
- Evidence summary
- single-DTA
- Diagnostic-accuracy studies
- 2
- Reference standard
- One of five clinician investigators (four geriatricians, one geriatric nurse specialist) applying operationalised DSM-III-R delirium criteria within 24 hours of referral
- Citation
- Vermeersch PE The clinical assessment of confusion-A Applied nursing research : ANR. 1990;3(3):128-33. PMID 2400212
Copyright and reuse
- 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.