Bedside delirium screen. Free with attribution.
CAM (Confusion Assessment Method) is a validated clinical instrument used to assess bedside delirium screen. The instrument contains 4 items.
Source / attribution: Inouye SK et al., Ann Intern Med 1990 (free for clinical/educational use with attribution)
The instrument's primary construct — bedside delirium screen — is operationalized through a fixed set of items, each with a defined response format. This standardisation is what allows CAM scores to be compared meaningfully across clinicians, sites, and studies.
Like all screening or assessment instruments, CAM is a structured aid — not a diagnostic test in isolation. Results should be interpreted alongside history, examination, and clinical context. Where a score crosses an actionable threshold, the next step is typically a more detailed clinical evaluation rather than a definitive diagnosis.
Answer all 4 items below to see your CAM score and interpretation.
All scoring runs in your browser. No data is sent anywhere — close the tab and the answers are gone.
CAM uses weighted summation: each item carries a fixed weight that is added when the response indicates a positive finding.
Scoring notes: The simple total here is a heuristic; the formal CAM algorithm requires items 1 AND 2 plus 3 OR 4. Educational use only.
The cutoffs below are drawn from the published validation literature. Always interpret in clinical context.
| Score range | Band | Interpretation |
|---|---|---|
| 0–1 | Delirium unlikely | Delirium unlikely. |
| 2–2 | Delirium unlikely (need both 1 AND 2) | Need item 1 + 2 plus 3 OR 4 for delirium. |
| 3–4 | Delirium likely (if criteria met) | Likely delirium — confirm criteria pattern. |
This is an illustrative walkthrough, not a real patient. Follow the same four steps with your own answers — or use the live calculator at the top of this page.
Mark each item Yes or No. Each "Yes" adds the item's weight; each "No" adds 0. The example below uses illustrative answers.
| # | Item | Example response | Score |
|---|---|---|---|
| 1 | 1. Acute onset and fluctuating course | Yes | 1 |
| 2 | 2. Inattention | No | 0 |
| 3 | 3. Disorganized thinking | Yes | 1 |
| 4 | 4. Altered level of consciousness | No | 0 |
Add the weights from the items where you marked "Yes" (skip the "No" answers — they contribute 0).
1 + 0 + 1 + 0 = 2
Find the row in the interpretation table whose range contains your total:
Total = 2 falls between 2 and 2 → Delirium unlikely (need both 1 AND 2)
Delirium unlikely (need both 1 AND 2). Need item 1 + 2 plus 3 OR 4 for delirium.
A score is one input alongside history and examination. CAM supports clinical judgment — it does not replace it.
If CAM doesn't fit your context, related instruments in geriatrics include:
| Scale | Measures | Items | Time |
|---|---|---|---|
| Barthel Index | Functional independence in ADLs | 10 | — |
| GDS-15 | Depression screening in older adults | 15 | — |
| Katz ADL | Functional independence in basic ADLs | 6 | — |
| Lawton IADL | Functional independence in instrumental ADLs | 8 | — |
| Timed Up and Go | Mobility and fall risk in older adults | 1 | — |
| APGAR Score | Rapid assessment of newborn at 1 and 5 min | 5 | — |
| ASA Physical Status | Pre-operative health status | 1 | — |
| CHA2DS2-VASc | Annual stroke risk in non-valvular atrial fibrillation | 8 | — |
CAM (Confusion Assessment Method) is a validated instrument that assesses bedside delirium screen.
CAM contains 4 items.
Scores of 3–4 fall in the "Delirium likely (if criteria met)" band. Likely delirium — confirm criteria pattern.
Scores of 0–1 fall in the "Delirium unlikely" band. Delirium unlikely.
CAM is free to use with attribution. Inouye SK et al., Ann Intern Med 1990 (free for clinical/educational use with attribution)
Inouye SK et al. Ann Intern Med. 1990;113(12):941-948.
No. CAM is a structured assessment aid. A score is one input alongside history, examination, and clinical context. Treatment decisions should never rest on a screening score alone.
CAM is supported by the following peer-reviewed sources: