CHADS2 Score Calculator
Calculate the CHADS2 score to estimate stroke risk in patients with atrial fibrillation, used to help guide anticoagulation therapy decisions. Educational reference only.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| CHADS2 Score Calculator | — | CHADS2 = Sum of risk factors (0-6 points) | score 0-6 |
Step-by-Step Examples
No CHF, no HTN, age<75, no diabetes, no prior stroke.
- Total = 0+0+0+0+0 = 0
- Low estimated annual stroke risk (~1.9%)
- May not require anticoagulation per some guidelines, though CHA2DS2-VASc often preferred for refined assessment
Hypertension present, age≥75, no other factors.
- Total = 0+1+1+0+0 = 2
- Moderate estimated annual stroke risk (~4.0%)
- Often warrants anticoagulation consideration per guidelines
CHF, hypertension, diabetes, and prior stroke history.
- Total = 1+1+0+1+2 = 5
- High estimated annual stroke risk (~12.5%)
- Strong indication for anticoagulation therapy consideration
Real-World Applications
Common Mistakes to Avoid
CHA2DS2-VASc has largely superseded CHADS2 in clinical guidelines as it better identifies truly low-risk patients and includes additional risk factors (vascular disease, sex, age 65-74).
Treatment decisions must also weigh bleeding risk (often assessed with HAS-BLED score), patient preferences, and overall clinical context — never based on stroke risk score alone.
This is an educational reference tool. Actual anticoagulation decisions require comprehensive evaluation by qualified healthcare providers considering the full clinical picture.