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CRB-65 severity score for community-acquired pneumonia risk stratification, usable without laboratory testing (Confusion, Respiratory rate, Blood pressure, age 65+).
Clinical decision-support tool for qualified healthcare professionals. Results are not a diagnosis and should not replace professional clinical judgment.
CRB-65 is the lab-free version of CURB-65 and is intended for primary care/out-of-hospital use. Score 0 = low mortality risk (approximately 1%), consider outpatient care. Score 1–2 = intermediate risk (approximately 8%), consider hospital admission. Score 3–4 = high risk (approximately 30%), urgent hospital admission and consider ICU.
Specialty
Emergency MedicineCategory
EmergencyDifficulty
Basic
Estimated Time
30 seconds
Version
1.0
Last Updated
2026-08-15
Formula
Keywords
Normal Range
0–4 points
Stratifies severity and mortality risk in community-acquired pneumonia without requiring laboratory testing.
CRB-65 adds one point each for new confusion, respiratory rate 30/min or higher, systolic blood pressure below 90 mmHg or diastolic 60 mmHg or lower, and age 65 years or older, for a total of 0-4. Higher scores indicate greater pneumonia mortality risk.
New-onset confusion; Yes adds one point.
Respiratory rate in breaths/min; 30 or higher adds one point.
Systolic blood pressure in mmHg; below 90 adds one point.
Diastolic blood pressure in mmHg; 60 or lower adds one point.
Age in years; 65 or older adds one point.
Score 0: low risk (mortality ~1%), consider outpatient care. Score 1–2: intermediate risk (mortality ~8%), consider hospital admission. Score 3–4: high risk (mortality ~30%), urgent admission and consider ICU.
CRB-65 enables rapid, lab-free risk stratification of pneumonia at the point of care, guiding the decision between outpatient treatment and hospital admission.
A 70-year-old man with pneumonia is confused, has a respiratory rate of 28/min, blood pressure 110/70 mmHg.
Inputs:
Expected Result: CRB-65 score 2 — intermediate risk. Consider hospital admission.
CRB-65 is the laboratory-free version of CURB-65. Both score confusion, respiratory rate, blood pressure, and age 65 or older, but CURB-65 adds a urea component. Dropping urea means CRB-65 can be completed in primary care or out of hospital without blood tests, at the cost of slightly reduced discrimination. The four items and the 0 to 4 total are otherwise the same, so the two scores should not be mixed.
A score of 0 indicates low mortality risk, about 1 percent, and outpatient care can be considered. A score of 1 to 2 indicates intermediate risk, about 8 percent, and hospital admission should be considered. A score of 3 to 4 indicates high risk, about 30 percent, and warrants urgent admission with consideration of ICU care. These estimates support but do not replace clinical judgment about the individual patient.
Age 65 or older is one of the four criteria in the score, so it adds a point by design. This means an otherwise stable older patient can score 1 without having any abnormal physiology, which is a recognized limitation of the tool. The age point should be interpreted alongside the clinical picture, and because CRB-65 does not measure oxygenation, oxygen requirements should always be assessed separately.
Disclaimer: This calculator is intended for educational and clinical decision support purposes only. CRB-65 guides site-of-care triage but does not replace assessment of oxygenation and hemodynamic stability.