What is the definition of CURB-65 (Confusion, Uremia, Respiratory rate, Blood pressure, and age 65 or older)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 24, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

CURB-65 is a clinical prediction rule used to assess the severity of community-acquired pneumonia, evaluating Confusion, Urea, Respiratory rate, Blood pressure, and age ≥65 years, with a score of 0-5 determining the need for hospital admission or outpatient treatment. The acronym stands for the five criteria evaluated: Confusion (new-onset), Urea (blood urea nitrogen) >7 mmol/L (>19 mg/dL), Respiratory rate ≥30 breaths per minute, Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg), and age ≥65 years. Each criterion is assigned one point, creating a score from 0-5.

Key Points

  • Patients scoring 0-1 are considered low risk and can typically be treated as outpatients 1.
  • Those scoring 2 should be considered for short hospital stays or supervised outpatient treatment 1.
  • Patients with scores of 3-5 have higher mortality risk and generally require hospitalization, with scores of 4-5 often indicating need for intensive care unit admission 1.
  • CURB-65 helps standardize clinical decision-making by objectively quantifying pneumonia severity, though it should complement rather than replace clinical judgment 1.
  • The parameters reflect physiological stress, organ dysfunction, and age-related vulnerability that correlate with poorer outcomes in pneumonia patients.

Comparison with Other Criteria

  • The CURB-65 score is compared to the Pneumonia Severity Index (PSI) in terms of predicting mortality and guiding admission decisions 1.
  • While the PSI includes 20 different variables, the CURB-65 criteria are easily remembered and have been shown to be effective in determining the need for hospital admission 1.

From the Research

Definition of CURB-65

  • CURB-65 is a clinical prediction rule used to stratify patients with pneumonia by expected mortality 2
  • It assesses the following parameters:
    • Confusion
    • Uremia (elevated blood urea nitrogen)
    • Respiratory rate (≥ 30/min)
    • Blood pressure (low, systolic < 90 mmHg or diastolic ≤ 60 mmHg)
    • Age (≥ 65 years)

Components and Scoring

  • Each parameter is assigned a point, and the total score ranges from 0 to 5 3
  • The score is used to predict the severity of community-acquired pneumonia (CAP) and guide management decisions

Comparison with Other Scoring Systems

  • CURB-65 has been compared to other scoring systems, such as A-DROP and PSI, and has been shown to be a useful tool for predicting mortality and severity of CAP 4, 3
  • The expanded CURB-65 score, which includes additional parameters such as LDH and albumin levels, has been shown to have superior predictive efficiency compared to the original CURB-65 score 4

Clinical Application

  • CURB-65 can be used to identify patients with CAP who are at low risk of mortality and may be suitable for outpatient treatment 5
  • The score can also be used to predict the need for critical care interventions, such as ICU admission and mechanical ventilation 2
  • A new scoring system, CURBS-65, which includes oxygenation parameters, has been proposed as a potential improvement over the original CURB-65 score 6

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.