University of Iowa
Department of Family Medicine

FPInfo: Resources to support patient care

General Clinical Resources - Clinical Scoring Instruments and Decision Rules


CHADS2 Score

 

CHADS2 Score for Atrial Fibrillation Stroke Risk

The CHADS2 score is a validated clinical prediction rule for determining the risk of stroke and who should be anticoagulated.

It assigns points (0-6) depending on the presence or absence of co-morbidities.

 

CHADS2 score

CHF Hx

+1

HTN Hx

+1

Age 75 or >75 yrs old

+1

Diabetes Mellitus Hx

+1

Stroke previously or TIA Hx

+2

 

CHADS2 scores, stroke risk, and risk levels

CHADS2 score

Stroke risk
per 100 pt-yr

CHADS2 risk level

Anticoagulation recommended

0

1.9

Low

ASA

1

2.8

Moderate

ASA or Warfarin

2

4.0

High

Warfarin

3

5.9

High

Warfarin

4

8.5

High

Warfarin

5

12.5

High

Warfarin

6

18.2

High

Warfarin

 

 

Source: Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ (2001). "Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation". JAMA 285 (22): 286470. PMID 11401607