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.
Frank E, Winkleby MA, Altman DG, Rockhill B, Fortmann SP.Frank E, et al. Among authors: fortmann sp.JAMA. 1991 Dec 11;266(22):3139-44.JAMA. 1991.PMID: 1956100
Frank E, Winkleby MA, Fortmann SP, Rockhill B, Farquhar JW.Frank E, et al. Among authors: fortmann sp.JAMA. 1992 Sep 23-30;268(12):1566-72.JAMA. 1992.PMID: 1518111
Williams EL, Winkleby MA, Fortmann SP.Williams EL, et al. Among authors: fortmann sp.Am J Epidemiol. 1993 May 15;137(10):1056-67. doi: 10.1093/oxfordjournals.aje.a116609.Am J Epidemiol. 1993.PMID: 8317435