Nat. Rev. Cardiol. 11, 693–703 (2014); published online 4 November 2014; doi:10.1038/nrcardio.2014.170

In the version of this article initially published online and in print, the text “NNH (intracranial haemorrhage)” in the key of Figure 3 should have read “NNT (intracranial haemorrhage)”. The error has been corrected for the HTML and PDF versions of the article.