CURB-65 Calculator (Pneumonia Severity)

CURB-65 = Confusion + Urea>7 + RR≥30 + BP<90/60 + Age≥65. Lim 2003 Thorax. Predicts 30-day pneumonia mortality.

Inputs

Result

CURB-65
0
30-day mortality ~0.7%. Outpatient — low mortality.
  • Confusion (+1)0
  • Urea > 7 mmol/L (+1)0
  • RR ≥ 30 (+1)0
  • BP < 90/60 (+1)0
  • Age ≥ 65 (+1)0
  • Total0
  • 30-day mortality0.7%
  • DispositionOutpatient — low mortality.

Step-by-step

  1. Sum 5 binary criteria: max 5.
  2. Score = 0 + 0 + 0 + 0 + 0 = 0.
  3. 30-day mortality (Lim 2003): 0.7%.

How to use this calculator

  • Assess each criterion at presentation.
  • Read score + 30-day mortality estimate.
  • Use alongside oxygenation + clinical judgment for admission decisions.

About this calculator

CURB-65 stratifies community-acquired pneumonia (CAP) by 30-day mortality and informs admission decisions. Source: Lim WS et al., "Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study." Thorax 2003;58(5):377-82. Validated in 1,068 patients from 3 countries. Mortality bands: 0 (0.7%), 1 (2.1%), 2 (9.2%), 3 (14.5%), 4 (40%), 5 (57%). BTS/IDSA guidelines: score 0-1 outpatient, 2 ward (short stay), 3-5 inpatient (ICU consider ≥3-4). Variant CRB-65 omits urea (no labs needed; useful in primary care). **Not medical advice — clinical context (oxygenation, comorbidities) drives admission decisions.**

Frequently asked

Lim WS et al., Thorax 2003;58:377-82. International (UK/NL/NZ) prospective validation in 1,068 CAP patients.

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