Aspirin v placebo for primary prevention of cardiovascular disease in women at mean 10 years*

OutcomesAspirinPlaceboRRR (95% CI)NNT (CI)
Major cardiovascular event†2.4%2.6%9% (−3 to 20)Not significant
Stroke1.1%1.3%17% (1 to 31)445 (227 to 103 77)
Cardiovascular death0.60%0.63%5% (−22 to 26)Not significant
Transient ischaemic attack0.93%1.2%22% (6 to 36)385 (216 to 1687)
*GI  =  gastrointestinal; MI  =  myocardial infarction. Other abbreviations defined in glossary; RRR, RRI, NNT, NNH, and CI calculated from data in article.
†Major cardiovascular event  =  non-fatal myocardial infarction, non-fatal stroke, or death from cardiovascular causes.
Fatal or non-fatal MI0.99%0.97%2% (−16 to 25)Not significant
Transfusion for GI bleed0.6%0.5%40% (7 to 83)554 (305 to 2751)