Table 2.

Relationship of leukoaraiosis severity to 3-month functional outcome

vSS	3-month mRS 0-1, %		RR
	rt-PA	placebo
0	49.0 (98/200)	27.6 (56/203)	1.8 [1.4-2.3]
1	37.9 (11/29)	26.3 (10/38)	1.4 [0.7-2.9]
2	28.1 (9/32)	31.0 (9/29)	0.9 [0.4-2.0]
3	35.3 (6/17)	0.0 (0/11)	∞
4	28.6 (6/21)	21.7 (5/23)	1.3 [0.5-3.7]

mRS = Modified Rankin Scale; RR = relative risk. Figures in parentheses are numbers out of total, those in square brackets are 95% confidence intervals. Note that while the 95% confidence intervals exclude 1, the overall test of heterogeneity was neutral, indicating no interaction between rt-PA treatment and vSS (p = 0.395).