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.
Van Houtven CH, Norton EC.Van Houtven CH, et al.J Health Econ. 2004 Nov;23(6):1159-80. doi: 10.1016/j.jhealeco.2004.04.008.J Health Econ. 2004.PMID: 15556241
Van Houtven CH, Norton EC.Van Houtven CH, et al.J Health Econ. 2008 Jan;27(1):134-56. doi: 10.1016/j.jhealeco.2007.03.002. Epub 2007 Mar 18.J Health Econ. 2008.PMID: 17462764