What CURB-65 measures
CURB-65 grades the severity of community-acquired pneumonia, meaning pneumonia caught outside the hospital. Developed by Lim and colleagues in 2003, it helps decide whether a patient can be treated at home, needs a hospital stay or may need intensive care.
The five items
| Letter | Item | Points |
|---|---|---|
| C | New confusion | 1 |
| U | BUN above 19 mg/dL (urea above 7 mmol/L) | 1 |
| R | Respiratory rate of 30 breaths per minute or more | 1 |
| B | Systolic blood pressure below 90 or diastolic 60 mmHg or less | 1 |
| 65 | Age 65 or older | 1 |
CRB-65 drops the urea item so it can be used in a clinic without a blood test.
Worked example
A 72-year-old patient, not confused, with a BUN of 15 mg/dL, a breathing rate of 24 per minute and a blood pressure of 115/70:
- Confusion 0, BUN 0, breathing rate 0, blood pressure 0.
- Age: 1 point.
- CURB-65 = 1: low severity. CRB-65 = 1 as well.
Interpreting the score
| CURB-65 | 30-day mortality | Usual management |
|---|---|---|
| 0 | 0.6% | home treatment |
| 1 | 2.7% | home treatment usually |
| 2 | 6.8% | short hospital stay or close follow-up |
| 3 | 14.0% | hospital treatment |
| 4 or 5 | 27.8% | hospital, consider intensive care |
Mortality figures come from the validation cohorts of the original study; outcomes today may be better, but the steps between levels remain useful.
What the score leaves out
CURB-65 ignores oxygen levels, which many clinicians check first, as well as chronic illnesses, pregnancy, the ability to take antibiotics by mouth and whether someone at home can help. The Pneumonia Severity Index is a longer alternative used widely in the United States. In every case, the score supports clinical judgment and does not replace it.
Seeking care
Shortness of breath at rest, chest pain, confusion, bluish lips or a high fever that does not come down are reasons to seek urgent care, whatever the score.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.