Table 3

Comparison of delta score to the follow-up score as well as the proposed A₂C₂S₂-VASc score to CHA₂DS₂-VASc score for discriminating a subsequent occurrence of ischaemic stroke in the 8202 matched patients with atrial flutter

Score	AUC, % (95% CI)	Delta AUC, % (95% CI)	IDI, % (95% CI)	Category-free NRI, % (95% CI)
CHA₂DS₂-VASc
Follow-up	55.6 (54.4 to 56.8)	Reference	Reference	Reference
Delta	60.2 (59.1 to 61.3)	4.60 (3.23 to 5.96)	2.97 (2.56 to 3.37)	25.9 (21.6 to 30.1)
Proposed A₂C₂S₂-VASc
Follow-up	57.9 (56.7 to 59.2)	Reference	Reference	Reference
Delta	61.0 (60.0 to 62.0)	3.05 (1.84 to 4.27)	3.40 (2.96 to 3.84)	22.2 (17.9 to 26.5)
Follow-up
CHA₂DS₂-VASc	55.6 (54.4 to 56.8)	Reference	Reference	Reference
Proposed A₂C₂S₂-VASc	57.9 (56.7 to 59.2)	2.34 (1.80 to 2.87)	0.93 (0.79 to 1.06)	25.6 (21.3 to 29.8)
Delta
CHA₂DS₂-VASc	60.2 (59.1 to 61.3)	Reference	Reference	Reference
Proposed A₂C₂S₂-VASc	61.0 (60.0 to 62.0)	0.79 (0.31 to 1.27)	1.36 (1.13 to 1.59)	35.4 (31.9 to 38.9)

All the results were significant at a p<0.001 level.
AUC, area under the curve; IDI, integrated discrimination index; NRI, net reclassification index.