Benefits of anticoagulation for 100 stroke patients
- Without anticoagulation 25 might have a stroke during 1st year
- With anticoagulation only 10 have a stroke ( i.e. a 60% relative risk reduction: 25-10/25 x100% = 60%). Some of these 10 may have a haemorrhagic stroke due to the anticoagulation
- Of the 25 who would have had a stroke, 15 avoid a stroke due to taking anticoagulation
- 85 did not have a stroke
- Treat 100 patients with anticoagulants for a year and benefit 15
- Treat about 6 patients in atrial fibrillation for a year with anticoagulation and prevent one of them having a stroke ( i.e. number needed to treat = 6)
- Each patient in atrial fibrillation has a 1 in 6 chance of benefit from taking anticoagulation for the first year after an ischaemic stroke or TIA
Page last reviewed: 24 Feb 2022
