ResusDoc / Clinical Scores / CURB-65
CURB-65 calculator
Scores the severity of community-acquired pneumonia to guide the decision between home treatment, admission, and critical care referral.
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Opens the CURB-65 card in the ResusDoc Clinical Scores app — scores as you tap, with the interpretation and next steps.
What it is used for
CURB-65 grades severity in adults with community-acquired pneumonia using five equally weighted variables, giving a total out of 5 that maps onto 30-day mortality. In UK practice it sits alongside BTS guidance and NICE NG138 and is used to answer a specific question: can this patient be treated at home? Note the UK unit convention — urea is scored in mmol/L. Where a urea result is not available, as in primary care, the CRB-65 variant omits it.
The five variables (1 point each, maximum 5)
| Component | Points |
|---|---|
| ConfusionNew — AMT 8 or less, or new disorientation | 1 |
| Urea above 7 mmol/LUK unit: mmol/L | 1 |
| Respiratory rate 30/min or more | 1 |
| Blood pressureSystolic under 90, or diastolic 60 or less (mmHg) | 1 |
| Age 65 or over | 1 |
How the score is interpreted
0–1
Low severity
Mortality risk under 3%. Suitable for home treatment with safety-netting and GP follow-up.
2
Moderate severity
Mortality risk around 9%. Consider admission; short-stay observation may be appropriate with good social support. Senior review recommended.
3
High severity
Mortality risk around 17%. Urgent admission. A score of 3 or more indicates severe CAP — consider HDU/ICU.
4–5
High severity
Mortality risk 41% or higher. Urgent admission, consider HDU/ICU, IV antibiotics per the local CAP pathway, and discuss with a microbiologist.
When not to use it
- CURB-65 measures severity, not diagnosis — it does not confirm pneumonia.
- It performs less well in the frail elderly and in immunosuppressed patients, where it can under-call severity.
- It should not override clinical concern or an abnormal NEWS2 in a patient who looks unwell with a low score.
Source: CURB-65 · BTS CAP guidelines · NICE NG138
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