CURB-65
Community-acquired pneumonia severity score for disposition decisions
Calculator
Why use it
Simple bedside tool for pneumonia severity assessment. Guides admission decisions for CAP. Recommended by BTS and NICE guidelines. Requires only basic clinical and lab data.
About
CURB-65 is a clinical prediction rule for estimating mortality of community-acquired pneumonia (CAP) and guiding site-of-care decisions (outpatient vs. inpatient vs. ICU). It uses five simple criteria: Confusion, Urea, Respiratory rate, Blood pressure, and age ≥ 65.
When to use
- Patients diagnosed with community-acquired pneumonia
- Disposition decision: outpatient vs. hospital vs. ICU
- Risk stratification at time of ED presentation
Formula
Pearls & pitfalls
- CRB-65 (without urea) can be used when lab results are unavailable — useful in primary care.
- CURB-65 may underestimate severity in young patients with severe sepsis.
- Does not account for comorbidities, social factors, or oxygenation — use clinical judgment alongside.
- PSI/PORT Score is an alternative that accounts for more variables but is more complex.
- Consider ICU admission criteria separately (ATS/IDSA major/minor criteria).
Next steps
Score 0-1: Consider outpatient treatment. Score 2: Short inpatient stay or hospital-supervised outpatient. Score 3-5: Hospitalize; score 4-5 consider ICU admission.
Evidence
Derived from a multicentre study of 1,068 patients (Lim et al., Thorax 2003). Validated internationally. BTS/NICE recommended for CAP severity assessment. 30-day mortality ranges from <1% (score 0) to >40% (score 5).