san_francisco_syncope_rule: San Francisco Syncope Rule

In cliot: Clinical Indices and Outcomes Tools

San Francisco Syncope Rule

Description

Calculates the San Francisco Syncope Rule result to predict the risk of serious outcomes at 7 days in patients presenting with syncope. The rule uses the CHESS mnemonic: CHF history, Hematocrit < 30, ECG abnormal, Shortness of breath, and Systolic BP < 90. Presence of any single factor classifies the patient as High Risk.

Usage

san_francisco_syncope_rule(history_chf, hematocrit, ecg_abnormal,
                           shortness_of_breath, systolic_bp)

Arguments

history_chf	Numeric (0 or 1). History of Congestive Heart Failure. (1 = Yes).
hematocrit	Numeric. Hematocrit percentage. (< 30% is a positive predictor).
ecg_abnormal	Numeric (0 or 1). Abnormal ECG (e.g., non-sinus rhythm or new changes). (1 = Yes).
shortness_of_breath	Numeric (0 or 1). History of shortness of breath. (1 = Yes).
systolic_bp	Numeric. Systolic blood pressure at triage in mmHg. (< 90 mmHg is a positive predictor).

Value

A list containing:

Risk_Classification	"High Risk" (if any criteria met) or "Low Risk".
Criteria_Present	List of specific positive predictors identified.
Test_Characteristics	Sensitivity and Specificity metrics.

References

Quinn J, McDermott D, Stiell I, Kohn M, Wells G. Prospective validation of the San Francisco Syncope Rule to predict patients with serious outcomes. Ann Emerg Med. 2006;47(5):448-454. doi:10.1016/j.annemergmed.2005.11.019

Examples

# Example 1: High Risk (CHF history)
# Hx CHF (1), Hct 40, Normal ECG, No SOB, SBP 120
san_francisco_syncope_rule(1, 40, 0, 0, 120)

# Example 2: Low Risk
# No Hx, Hct 42, Normal ECG, No SOB, SBP 110
san_francisco_syncope_rule(0, 42, 0, 0, 110)

# Example 3: High Risk (Low Hct and Low BP)
# No Hx, Hct 25, Normal ECG, No SOB, SBP 85
san_francisco_syncope_rule(0, 25, 0, 0, 85)

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