The score

  • The CHADS2 is a stroke-risk index for patients with atrial fibrillation.
  • It is estimated by summing the points assigned to several conditions.
  • The estimated annual risk of stroke ranges from:
    • 1.9% (score 0) - to - 18.2% (score 6)
Condition Points

CCF

1

Hypertension

1

Age >74

1

Diabetes mellitus

1

Prior stroke or TIA

2

CHADS2 Score Stroke Risk % NNT* for Wrafarin Recommendations
0
1.9
 77
NO anticoagulation
1
2.8
53
No treatment or oral anticoagulation therapy (oral anticoagulation preferred)
2
4.0
 37
Oral anticoagulation therapy recommended
3
5.9
25
4
8.5
17
5
12.5
12
6
18.2
8

*Number needed to treat with warfarin for 1 year to prevent 1 stroke.

Aspirin is recognised by Quality and Outcomes Framework and NICE guidelines but is no longer a recommended treatment for thromboprophylaxis in patients with atrial fibrillation.