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.
Beard CM, Heath H 3rd, O'Fallon WM, Anderson JA, Earle JD, Melton LJ 3rd.Beard CM, et al.Arch Intern Med. 1989 Aug;149(8):1887-90.Arch Intern Med. 1989.PMID: 2764660