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.
Berk DR, Hubert HB, Fries JF.Berk DR, et al. Among authors: fries jf.J Gerontol A Biol Sci Med Sci. 2006 Jan;61(1):97-102. doi: 10.1093/gerona/61.1.97.J Gerontol A Biol Sci Med Sci. 2006.PMID: 16456200
Lane NE, Bloch DA, Hubert HB, Jones H, Simpson U, Fries JF.Lane NE, et al. Among authors: fries jf.Am J Med. 1990 May;88(5):452-9. doi: 10.1016/0002-9343(90)90422-a.Am J Med. 1990.PMID: 2337104