M+QuickMedCalc
Educational reference only. Not a diagnostic tool. See full disclaimer.
All calculators
EmergencyCURB-65

CURB-65 Score

Assess severity of community-acquired pneumonia.

Criteria

CURB-65 Score

0

Low severity — consider outpatient treatment

About

The CURB-65 score is a clinical prediction rule for pneumonia severity in community-acquired pneumonia (CAP), used at the time of presentation to guide initial disposition: outpatient versus hospital admission versus ICU evaluation. This CURB-65 calculator gives 1 point for each letter — Confusion (new mental status change), Urea > 7 mmol/L (BUN > 19 mg/dL), Respiratory rate ≥30/min, Blood pressure (SBP < 90 or DBP ≤ 60 mmHg), and age ≥65 — for a maximum of 5. Use CURB-65 in any adult presenting with CAP. The 2019 IDSA/ATS guideline prefers the Pneumonia Severity Index (PSI / PORT score) as the primary decision tool because of stronger evidence in identifying low-risk patients, while the British Thoracic Society and NICE continue to recommend CURB-65 for its bedside simplicity. CURB-65 is not validated for hospital-acquired or ventilator-associated pneumonia, in immunocompromised patients with opportunistic infection, or in children. Clinical judgement should override the score when social factors (homelessness, inability to take oral medications, lack of follow-up), comorbidity, or hypoxaemia not captured by the score warrant admission.

Formula

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

Interpretation

ScoreSeverityDisposition / clinical action
0 – 1Low (~1.5% 30-d mortality)Outpatient management with oral antibiotics
2Moderate (~9.2%)Consider short hospital admission or supervised outpatient management
3 – 5High (~22%)Hospitalise; score 4–5 prompts ICU evaluation

Per-score 30-day mortality in the Lim 2003 derivation cohort: 0 → 0.7%, 1 → 3.2%, 2 → 13%, 3 → 17%, 4 → 41.5%, 5 → 57%.

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.
  2. Metlay JP, et al. Diagnosis and Treatment of Adults with Community-acquired Pneumonia. An Official Clinical Practice Guideline of the ATS and IDSA. Am J Respir Crit Care Med. 2019;200(7):e45-e67.
  3. Aujesky D, et al. Prospective comparison of three validated prediction rules for prognosis in community-acquired pneumonia. Am J Med. 2005;118(4):384-392.

FAQ

Related Calculators

Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.