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.
Montez-Rath M, Christiansen CL, Ettner SL, Loveland S, Rosen AK.Montez-Rath M, et al.BMC Med Res Methodol. 2006 Oct 26;6:53. doi: 10.1186/1471-2288-6-53.BMC Med Res Methodol. 2006.PMID: 17067394Free PMC article.