Table 1.

Relationship between time of symptom onset and functional. outcome (measured by modified Rankin scale), after reperfusion therapy with IV-tPA.

Time (minutes after onset)	Number needed to treat	Number needed to harm
0–90	3.6	65
91–180	4.3	38
181–270	5.9	30
271–360	19.3	14

Table based on work by Lansberg et al. (15).