Table 2. Chads 2 score stroke risk per 100 person years/on or off warfarin.[47].

0 Points:	0.25 on warfarin; 0.49 no
1 Point:	0.72 on warfarin; 1.52 no
2 Points:	1.27 on warfarin; 2.50 no
3 Points:	2.20 on warfarin; 5.27 no
4 Points:	2.35 on warfarin; 6.02 no
5–6 Points:	4.60 on warfarin; 6.88 no