0points

Low risk group:0.6% 30-day mortality.

Consider outpatient treatment.

1points

Low risk group:2.7% 30-day mortality.

Consider outpatient treatment.

2points

Moderate risk group:6.8% 30-day mortality.

Consider inpatient treatment or outpatient with close followup.

3points

Severe risk group:14.0% 30-day mortality.

Consider inpatient treatment with possible intensive care admission.

4points

Highest risk group:27.8% 30-day mortality.

Consider inpatient treatment with possible intensive care admission.

5points

Highest risk group:27.8% 30-day mortality.

Consider inpatient treatment with possible intensive care admission.

The CRB-65 calculator can be used to stratify a patient’s community acquired pneumonia

The CRB-65 Score includes points for confusion and blood urea nitrogen, which in the acutely ill elderly patient, could be due to a variety of factors. An alternative scoring system, SOAR, circumvents those two parameters. It uses low systolic BP (S) and poor oxygenation (PaO2:FIO2) (O), advancing age (A), high respiratory rate (R).

CRB-65 does not assign points for co-morbid illness and nursing home residence, as the original study did account for many of these conditions.

CRB-65 may not identify patients requiring ICU admission as well as the PSI.

CRB-65 is fast to compute, requires likely already-available patient information, and provides an excellent risk stratification of community acquired pneumonia. It can facilitate better utilization of resources and treatment initiation.

In comparison to the PSI, CRB-65 offers equal sensitivity of mortality prediction due to community acquired pneumonia. Notably, CRB-65 (74.6%) has a higher specificity than PSI (52.2%).

Confusion
Respiratory Rate ≥ 30
Systolic BP < 90 mmHg or Diastolic BP ≤ 60 mmHg
Age ≥ 65
Is this a COVID-19 patient?For research purposes only; answer does NOT impact results.
ADVICE

While many pneumonias are actually viral in nature, typical practice is to provide a course of antibiotics given the pneumonia may be bacterial.

Disposition (inpatient vs. outpatient) often dictates further care and management -- including lab testing, blood cultures, etc.

MANAGEMENT

The CURB-65 scores range from 0 to 5. Assign points as in the table based on confusion status, urea level, respiratory rate, blood pressure, and age. Clinical management decisions can be made based on the score, as described in the validation study below:

ScoreRiskNew Column
0 or 11.5% mortalityOutpatient care
29.2% mortalityInpatient vs. observation admission
≥ 322% mortalityInpatient admission with consideration for ICU admission with score of 4 or 5
CRITICAL ACTIONS

For patients scoring high on CURB-65, it would be prudent to ensure initial triage has not missed the presence of sepsis.

FORMULA

Addition of the selected points, as above.

FACTS & FIGURES

Score interpretation (as per derivation study):

CURB-65 scoreMortality RiskRecommendation per Derivation Study
00.60%Low risk; consider home treatment
12.70%Low risk; consider home treatment
26.80%Short inpatient hospitalization or closely supervised outpatient treatment
314.00%Severe pneumonia; hospitalize and consider admitting to intensive care
4 - 527.80%Severe pneumonia; hospitalize and consider admitting to intensive care
EVIDENCE APPRAISAL

The original study was a retrospective review of three prospective studies of CAP in the UK, New Zealand, and the Netherlands. It included a total of 1068 patients. A five-point score based on confusion, urea, respiratory rate, blood pressure, and age was developed to stratify patients into different treatment group based on mortality risk. The validation study was done in India and included 150 patients.

CURB-65’s original study including co-morbidity variables like chronic lung disease, chronic liver disease, CHF, CVD, and DM, and these were controlled for when developing the relevant criteria for the risk stratification that ultimately led to CURB-65’s risk factors.

Several other more recent validation studies in several different countries show increasing mortality and even need for intubation with increasing CURB-65 scores, ranging from 0-1.1% (CURB-65 score = 0) to 17-60% (CURB-65 score = 5), with over 3100 patients in these studies when combined.