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.
Hollingworth W, Campbell JD, Kowalski J, Ravelo A, Girod I, Briggs A, Sullivan SD.Hollingworth W, et al. Among authors: campbell jd.Qual Life Res. 2010 Apr;19(3):323-31. doi: 10.1007/s11136-010-9590-z. Epub 2010 Jan 22.Qual Life Res. 2010.PMID: 20094804Clinical Trial.