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CURB-65 Score — Free Online Calculator

Criteria

CURB-65 Score

0

Low severity — consider outpatient treatment

About This Calculator

The CURB-65 score is a clinical prediction rule for assessing the severity of community-acquired pneumonia (CAP). It helps determine the appropriate site of care: outpatient, general ward, or intensive care unit. Each letter represents a criterion: Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65.

Formula

CURB-65 = Sum of applicable criteria (0–5)

Interpretation

ScoreSeverityDisposition
0 – 1LowOutpatient (~1.5% mortality)
2ModerateConsider admission (~9.2% mortality)
3 – 5HighHospital/ICU (~22% mortality)

References

  1. Lim WS, et al. Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study. Thorax. 2003;58(5):377-382.

Frequently Asked Questions

What does each letter in CURB-65 stand for?

C = Confusion (new mental confusion), U = Urea >7 mmol/L (BUN >19 mg/dL), R = Respiratory rate ≥30/min, B = Blood pressure (systolic <90 or diastolic ≤60 mmHg), 65 = Age ≥65 years. Each criterion scores 1 point, for a maximum of 5.

How does CURB-65 guide disposition decisions?

Score 0–1: low risk, suitable for outpatient treatment. Score 2: consider short hospital admission or closely supervised outpatient care. Score 3–5: severe pneumonia, hospitalize; scores 4–5 should prompt ICU evaluation.

What is CRB-65 and when is it used?

CRB-65 omits the urea criterion (which requires blood work) and can be used in primary care or pre-hospital settings. Score 0: very low risk (outpatient). Score 1–2: increased risk, consider referral. Score 3–4: high risk, urgent hospital admission.

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⚠ Medical Disclaimer

This tool is for educational and informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional for clinical decisions.