| Outcome |
Control event rate |
No of events avoided |
NNTB or NNTH |
| |
|
Per 1000 people treated (95% CI) |
Data are number needed to treat to benefit (NNTB) (95% CI) unless otherwise indicated. NNTH = number needed to treat to harm |
| |
Estimated from the average of the control event rate in the 2 largest trials (CAST 1997 and IST 1997) |
Estimated by applying the odds ratio for the outcome for studies of aspirin. Calculator is available at: http://www.dcn.ed.ac.uk/csrg/entity/entity_NNT2.asp |
Estimated by applying the odds ratio for the outcome for studies of aspirin. Calculator is available at: http://www.dcn.ed.ac.uk/csrg/entity/entity_NNT2.asp |
| Death or dependence at end of follow‐up |
0.47 |
13 (3 to 23) |
79 (43 to 400) |
| Deaths from all causes during follow‐up |
0.13 |
9 (2 to 15) |
108 (66 to 436) |
| Pulmonary embolism during treatment period |
0.01 |
1 (0 to 2) |
693 (427 to 6700) |
| Recurrent ischaemic/unknown stroke during treatment period |
0.03 |
7 (4 to 10) |
140 (104 to 248) |
| Symptomatic intracranial haemorrhage during treatment period |
0.01 |
‐2 (i.e. 2 extra) (‐4 to 0) |
NNTH 574 (254 to 126 010) |
| Any recurrent stroke/intracranial haemorrhage during treatment |
0.04 |
5 (1 to 8) |
200 (123 to 868) |
| Major extracranial haemorrhage during treatment period |
0.01 |
‐4 (i.e. 4 extra) (‐7 to ‐2) |
NNTH 245 (153 to 481) |
| Complete recovery from stroke (post hoc) |
0.26 |
11 (2 to 21) |
89 (49 to 523) |
