CRB-65
Community-acquired pneumonia severity for primary care.
What it is for
Informs home vs hospital for CAP alongside clinical judgement (NICE NG250). No bloods needed.
Use the working calculator
The working CRB-65 calculator is on our calculators page. It is free and needs no account. Enter the values and it shows the result with the reading that goes with it.
The calculators are free. The trial opens the protocols and pathways they link to.What you enter
The calculator asks for 4 items.
- Confusion — AMT ≤ 8 or new disorientation (1 point)
- Respiratory rate ≥ 30 / min (1 point)
- BP — SBP < 90 OR DBP ≤ 60 (1 point)
- Age ≥ 65 (1 point)
How the result is read
The result is shown as CRB-65, out of a maximum of 4.
The calculator reads each total as follows. Where a single answer changes the reading (for example sex, age or one extreme value), the working calculator says so.
| Total | Band | What the calculator says |
|---|---|---|
| 0 | Low risk (less than 1% 30-day mortality) | NICE NG250 1.2.3: consider primary care-led services with safety netting advice, using clinical judgement. See the pneumonia protocol. 30-day mortality less than 1%. Refer to hospital if any symptoms or signs suggest a more serious illness, for example sepsis or cardiorespiratory failure (NG250 1.2.4). |
| 1 | Intermediate risk (1% to 10% 30-day mortality) | NICE NG250 1.2.3: consider primary care-led services with safety netting advice, or referral to a virtual ward, a same-day emergency care (SDEC) unit, a hospital at home service or hospital. A shared decision using clinical judgement; the score can be affected by other factors, for example comorbidities or pregnancy. |
| 2 | Intermediate risk (1% to 10% 30-day mortality) | NICE NG250 1.2.3: consider referral to hospital for adults with a CRB65 score of 2 or more. A shared decision using clinical judgement; the score can be affected by other factors, for example comorbidities or pregnancy. |
| 3 to 4 | High risk (more than 10% 30-day mortality) | NICE NG250 1.2.3: consider referral to hospital for adults with a CRB65 score of 2 or more. 30-day mortality more than 10%. |
Sources
These are the sources the calculator cites. Check the current version before relying on a threshold.
Related
For qualified clinicians. A score supports a clinical decision and does not make it: check the inputs, read the cited source, and use the tools in your clinical system for patient care where one is provided.