crb65_pneumonia_severity: CRB-65 Score for Pneumonia Severity

In cliot: Clinical Indices and Outcomes Tools

CRB-65 Score for Pneumonia Severity

Description

Calculates the CRB-65 score to stratify the severity of community-acquired pneumonia (CAP). Unlike the CURB-65 score, CRB-65 does not require blood urea nitrogen (BUN) measurement, making it suitable for use in primary care or settings without immediate laboratory access.

Usage

crb65_pneumonia_severity(confusion, respiratory_rate, systolic_bp,
                         diastolic_bp, age)

Arguments

confusion	Numeric (0 or 1). Recent confusion. (1 = Yes, +1 point).
respiratory_rate	Numeric. Respiratory rate in breaths per minute. (>= 30 bpm adds +1 point).
systolic_bp	Numeric. Systolic blood pressure in mmHg. (< 90 mmHg contributes to the BP criterion).
diastolic_bp	Numeric. Diastolic blood pressure in mmHg. (<= 60 mmHg contributes to the BP criterion). Note: The BP criterion is met if SBP < 90 OR DBP <= 60 (+1 point).
age	Numeric. Patient age in years. (>= 65 years adds +1 point).

Value

A list containing:

CRB65_Score	The calculated score (Range 0-4).
Risk_Level	Classification (Very Low, Increased, High).
Est_Mortality_30_Day	Estimated mortality percentage.
Recommendation	Guidance on disposition (Home vs. Hospital).

References

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(5):377-382. doi:10.1136/thorax.58.5.377

Examples

# Example 1: High Risk
# 70yo (+1), Confused (+1), RR 32 (+1), BP 100/70 (0)
# Score = 3
crb65_pneumonia_severity(1, 32, 100, 70, 70)

# Example 2: Low Risk
# 40yo (0), Not confused (0), RR 18 (0), BP 120/80 (0)
# Score = 0
crb65_pneumonia_severity(0, 18, 120, 80, 40)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.