chads2_score: CHADS2 Score for Atrial Fibrillation Stroke Risk

In cliot: Clinical Indices and Outcomes Tools

CHADS2 Score for Atrial Fibrillation Stroke Risk

Description

Calculates the CHADS2 score to estimate the risk of stroke in patients with non-rheumatic atrial fibrillation. The score is used to determine whether anticoagulation therapy (e.g., warfarin, aspirin) is indicated.

Usage

chads2_score(chf, hypertension, age, diabetes, stroke_tia)

Arguments

chf	Numeric (0 or 1). History of Congestive Heart Failure. (1 = Yes, +1 point).
hypertension	Numeric (0 or 1). History of Hypertension. (1 = Yes, +1 point).
age	Numeric. Patient age in years. (>= 75 years adds +1 point).
diabetes	Numeric (0 or 1). History of Diabetes Mellitus. (1 = Yes, +1 point).
stroke_tia	Numeric (0 or 1). History of prior Stroke or TIA. (1 = Yes, +2 points).

Value

A list containing:

CHADS2_Score	The calculated score (Range 0-6).
Risk_Category	Classification (Low, Moderate, High).
Annual_Stroke_Risk	Estimated annual stroke risk percentage without anticoagulation.

References

Gage BF, Waterman AD, Shannon W, et al. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864-2870. doi:10.1001/jama.285.22.2864

Examples

# Example 1: High Risk
# 76yo (+1), History of Stroke (+2)
# Score = 3
chads2_score(0, 0, 76, 0, 1)

# Example 2: Moderate Risk
# 60yo (0), Hypertension (+1)
# Score = 1
chads2_score(0, 1, 60, 0, 0)

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