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.
Giuffrida A, Gravelle H, Sutton M.Giuffrida A, et al. Among authors: gravelle h.J Health Econ. 2000 Nov;19(6):983-1006. doi: 10.1016/s0167-6296(00)00057-6.J Health Econ. 2000.PMID: 11186854
Ashworth M, Lea R, Gray H, Gravelle H, Majeed A.Ashworth M, et al. Among authors: gravelle h.Br J Gen Pract. 2003 Jun;53(491):468-70.Br J Gen Pract. 2003.PMID: 12939892Free PMC article.
Hann M, Gravelle H.Hann M, et al. Among authors: gravelle h.Br J Gen Pract. 2004 Dec;54(509):894-8.Br J Gen Pract. 2004.PMID: 15588532Free PMC article.