An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Teo KK, Yusuf S, Collins R, Held PH, Peto R.Teo KK, et al. Among authors: held ph.BMJ. 1991 Dec 14;303(6816):1499-503. doi: 10.1136/bmj.303.6816.1499.BMJ. 1991.PMID: 1838289Free PMC article.Clinical Trial.
Held PH, Yusuf S, Furberg CD.Held PH, et al.BMJ. 1989 Nov 11;299(6709):1187-92. doi: 10.1136/bmj.299.6709.1187.BMJ. 1989.PMID: 2513047Free PMC article.Clinical Trial.