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CURB-65

Estimates 30-day mortality in adults with community-acquired pneumonia and supports outpatient versus inpatient decisions. CRB-65 omits urea for primary care.

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Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.

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Method · Limits of application

CURB-65/Lim 2003: confusion, urea>7 mmol/L, RR≥30, blood pressure, age≥65; 0–5

The 2003 CURB-65 was derived and validated in hospitalized adults with community-acquired pneumonia, using initial-assessment data and 30-day mortality. Age ≥ 65 is a component of the score, not the minimum eligibility age. The original thresholds use urea > 7 mmol/L, respiratory rate ≥ 30/min and systolic BP < 90 or diastolic BP ≤ 60 mmHg. Exclusions and use in other populations require reading the full protocol.

Conditions of use

Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.

Documented parameters

Confusion (new disorientation to time, place or person)
Urea > 42 mg/dL (> 7 mmol/L)
Respiratory rate ≥ 30 breaths/min
Systolic blood pressure < 90 mmHg or diastolic ≤ 60 mmHg (Blood pressure)
Age ≥ 65 years

4/4 reference cases checked. Numerical tests are not clinical validation.

Sources and documentation

Documented formula

Transcribed from the source or a recorded revision; this is not a clinical recommendation.

One point per item: Confusion, Urea > 7 mmol/L, Respiratory rate ≥ 30/min, Blood pressure low (SBP < 90 or DBP ≤ 60 mmHg) and age ≥ 65. Maximum: 5.

The CRB-65 is the same score without urea (0–4), for use without laboratory tests.

References

Identifier: curb-65

Original clinical content: Brazilian Portuguese.

Method version

CURB-65/Lim 2003: confusion, urea>7 mmol/L, RR≥30, blood pressure, age≥65; 0–5

curb-65@native-2026-10-03+a39e88c8a7fa

Source for the active edition

The bibliographic edition identifies the source. By itself, it proves neither full conformity of the formula nor clinical approval.

Synthetic cases checked (4)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Confusion (new disorientation to time, place or person): No
Urea > 42 mg/dL (> 7 mmol/L): No
Respiratory rate ≥ 30 breaths/min: No
Systolic blood pressure < 90 mmHg or diastolic ≤ 60 mmHg (Blood pressure): No
Age ≥ 65 years: No

{
  "c": false,
  "u": false,
  "r": false,
  "b": false,
  "i": false
}

Expected result

{
  "crb": 0
}

Actual result

{
  "score": 0,
  "crb": 0
}

Case 2

reference-002

Inputs

Confusion (new disorientation to time, place or person): Yes
Age ≥ 65 years: Yes
Urea > 42 mg/dL (> 7 mmol/L): No
Respiratory rate ≥ 30 breaths/min: No
Systolic blood pressure < 90 mmHg or diastolic ≤ 60 mmHg (Blood pressure): No

{
  "c": true,
  "i": true,
  "u": false,
  "r": false,
  "b": false
}

Expected result

{
  "crb": 2
}

Actual result

{
  "score": 2,
  "crb": 2
}

Case 3

reference-003

Inputs

Confusion (new disorientation to time, place or person): Yes
Urea > 42 mg/dL (> 7 mmol/L): Yes
Respiratory rate ≥ 30 breaths/min: Yes
Age ≥ 65 years: Yes
Systolic blood pressure < 90 mmHg or diastolic ≤ 60 mmHg (Blood pressure): No

{
  "c": true,
  "u": true,
  "r": true,
  "i": true,
  "b": false
}

Expected result

{
  "crb": 3
}

Actual result

{
  "score": 4,
  "crb": 3
}

Case 4

reference-004

Inputs

Urea > 42 mg/dL (> 7 mmol/L): Yes
Confusion (new disorientation to time, place or person): No
Respiratory rate ≥ 30 breaths/min: No
Systolic blood pressure < 90 mmHg or diastolic ≤ 60 mmHg (Blood pressure): No
Age ≥ 65 years: No

{
  "u": true,
  "c": false,
  "r": false,
  "b": false,
  "i": false
}

Expected result

{
  "crb": 0
}

Actual result

{
  "score": 1,
  "crb": 0
}

Code and reproducibility

This tool’s code on GitHub

Download code and tests

Sources, version and reproduction instructions

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.