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.
Whitehead A, Omar RZ, Higgins JP, Savaluny E, Turner RM, Thompson SG.Whitehead A, et al. Among authors: turner rm.Stat Med. 2001 Aug 15;20(15):2243-60. doi: 10.1002/sim.919.Stat Med. 2001.PMID: 11468762
Turner RM, White IR, Croudace T; PIP Study Group.Turner RM, et al.Stat Med. 2007 Jan 30;26(2):274-89. doi: 10.1002/sim.2537.Stat Med. 2007.PMID: 16538700