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.
Cooper C, Coggon D.Cooper C, et al. Among authors: coggon d.Lancet. 1999 Jun 26;353(9171):2177-8. doi: 10.1016/S0140-6736(99)90094-6.Lancet. 1999.PMID: 10392979No abstract available.
Croft P, Coggon D, Cruddas M, Cooper C.Croft P, et al. Among authors: coggon d.BMJ. 1992 May 16;304(6837):1269-72. doi: 10.1136/bmj.304.6837.1269.BMJ. 1992.PMID: 1606427Free PMC article.