Summary of the CURB-65 Clinical Decision Rule

by Dr. Benjamin Schnapp

Which patients with Community Acquired Pneumonia are “high risk” and warrant admission?  Who is safe for the floors versus appropriate for ICU admimssion?

• Community acquired pneumonia occurs in a wide variety of different patients, from the young and healthy to the elderly and very ill.  However, not all of the proper dispositions are obvious, and it is essential to correctly identify those patients who are safe for discharge, as well as the correct level of care for admitted patients.
•  Despite the availibility of objective criteria for risk stratifying patients, there is a great deal of variability between physicians in hospitalization rates for community acquired pneumonia.

 CURB-65 Decision Rule for Predicting Mortality in Community Acquired Pneumonia

 1 point each for:

Confusion (new disorientation to person, place or time OR a Mental Test Score of < 8)

Urea > 7 mmol/l

Respiratory Rate ? 30

Blood pressure – systolic < 90 mm Hg OR diastolic ? 60

65 – Age ? 65

 ·        Score of 0-1: Likely safe for treatment at home

·        Score of 2: Hospital supervised treatment (short inpatient vs. supervised outpatient)

·        Score of 3 or more: Hospitalize as severe pneumonia (consider ICU, especially if score is 4 or greater)

Derivation:

·        Data from 3 previous multicenter prosective studies on community acquired pneumonia was combined into 1 large dataset.

·        The data was randomized into 2 groups, with 80% comprising the derivation group and 20% comprising the validation group.

·        Based on a previous study of community acquired pneumonia severity (mBTS), the CURB variables were analysed to determine their relation to 30 day mortality, and determined to be individually predictive.

·        12 additional variables known to be associated with pneumonia severity were also examined against the CURB variables to look for additional independent predictors of mortality.  Age of 65 or greater and albumin of < 30 g/dl were found to be independent predictors, and age was added to the decision rule.

·        Results were tested against the validation cohort to ensure validity, and scores were grouped to provide increased usability for clinicians

Results:

·        1068 patients studied

·        821 in derivation cohort, 247 in the validation cohort

·        Performance of the CURB-65 rule:

o       Score of 0-1 (low risk): n = 324, 5 died (1.5% mortality)

o       Score of 2 (intermediate risk): n  = 184, 17 died (9.2% mortality)

o       Score of 3 or more (high risk): n  = 210, 47 died (22% mortality)

Take home message:

30 day mortality in community acquired pneumonia can be predicted reliably using only a few criteria which are easily available when patients present to the emergency department.  CURB-65 can be used to aid appopriate disposition decisions for patients with pneumonia.

References:

1. Lim WS , van der Eerden MM , Laing R , et al.  Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study . Thorax. 2003;58:377–382
2. Dean NC, Jones JP, Aronsky D, et al.  Hospital Admission Decision for Patients With Community-Acquired Pneumonia: Variability Among Physicians in an Emergency Department  Annals of Emergency Medicine.  2012;59:35-41.