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.
Lawlor DA, Davey Smith G, Mitchell R, Ebrahim S.Lawlor DA, et al.Heart. 2004 Apr;90(4):381-8. doi: 10.1136/hrt.2002.009548.Heart. 2004.PMID: 15020510Free PMC article.
Emslie C, Mitchell R.Emslie C, et al.BMC Public Health. 2009 Feb 16;9:58. doi: 10.1186/1471-2458-9-58.BMC Public Health. 2009.PMID: 19220878Free PMC article.