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.
Hansen AW, Grønbæk M, Helge JW, Severin M, Curtis T, Tolstrup JS.Hansen AW, et al.J Med Internet Res. 2012 Oct 30;14(5):e145. doi: 10.2196/jmir.2109.J Med Internet Res. 2012.PMID: 23111127Free PMC article.Clinical Trial.