Table 3.

Classification performance, sensitivity, and specificity by score and risk category of Canadian TIA Score for subsequent stroke or carotid revascularisation within 7 days of index emergency department visit for transient ischaemic attack (n=7607)

Score	No (%) total patients	No (%) estimated stroke or carotid revascularisation ≤7 days	No (%) observed stroke or carotid revascularization ≤7 days	Risk category	Proportion of patients (%)	Sensitivity (95% CI)	Specificity (95% CI)
–3	4 (0.1)	0 (0.2)	0 (0)	Low	16.3	1.00 (0.98 to 1.00)	0.00 (0.00 to 0.00)
–2	2 (0.0)	0 (0.2)	0 (0)			1.00 (0.98 to 1.00)	0.00 (0.00 to 0.00)
–1	35 (0.5)	0 (0.3)	0 (0)			1.00 (0.98 to 1.00)	0.00 (0.00 to 0.00)
0	80 (1.1)	0 (0.4)	0 (0)			1.00 (0.98 to 1.00)	0.01 (0.00 to 0.01)
1	148 (1.9)	1 (0.5)	1 (0.7)			1.00 (0.98 to 1.00)	0.02 (0.01 to 0.02)
2	432 (5.7)	3 (0.7)	3 (0.7)			0.99 (0.97 to 1.00)	0.04 (0.03 to 0.04)
3	541 (7.1)	5 (0.9)	2 (0.4)			0.98 (0.94 to 0.99)	0.09 (0.09 to 0.10)
4	1245 (16.4)	15 (1.2)	15 (1.2)	Medium	72.1	0.97 (0.93 to 0.99)	0.17 (0.16 to 0.18)
5	1499 (19.7)	24 (1.6)	22 (1.5)			0.88 (0.83 to 0.93)	0.33 (0.32 to 0.34)
6	1042 (13.7)	23 (2.2)	28 (2.7)			0.76 (0.70 to 0.82)	0.53 (0.52 to 0.54)
7	920 (12.1)	26 (2.8)	25 (2.7)			0.61 (0.54 to 0.68)	0.67 (0.66 to 0.68)
8	778 (10.2)	29 (3.7)	34 (4.4)			0.47 (0.40 to 0.55)	0.79 (0.78 to 0.80)
9	467 (6.1)	23 (4.9)	27 (5.8)	High	11.6	0.29 (0.22 to 0.36)	0.89 (0.88 to 0.90)
10	228 (3.0)	15 (6.4)	11 (4.8)			0.14 (0.09 to 0.20)	0.95 (0.94 to 0.95)
11	117 (1.5)	10 (8.3)	10 (8.5)			0.08 (0.04 to 0.13)	0.98 (0.97 to 0.98)
12	54 (0.7)	6 (10.7)	2 (3.7)			0.02 (0.01 to 0.06)	0.99 (0.99 to 0.99)
13	13 (0.2)	2 (13.7)	1 (7.7)			0.01 (0.00 to 0.04)	1.00 (1.00 to 1.00)
14	2 (0.0)	0 (17.4)	1 (50.0)			0.01 (0.00 to 0.03)	1.00 (1.00 to 1.00)