James, Gareth D
Donaldson, Gavin C
Wedzicha, Jadwiga A
Nazareth, Irwin
Article History
Received: 17 September 2013
Revised: 5 March 2014
Accepted: 10 March 2014
First Online: 3 July 2014
Competing interests
: The authors declare no conflict of interest. This study was designed and analysed independent of any input from the National Institute of Health Research, who were the funders. No additional data were available. All authors have completed the Unified Competing Interest form and declare no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous 3 years; and no other relationships or activities that could appear to have influenced the submitted work. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.