Funding for this research was provided by:
Economic and Social Research Council (ES/L0008211/1)
Article History
Received: 31 July 2018
Accepted: 29 November 2018
First Online: 1 February 2019
Compliance with Ethical Standards
: The surveys have all received ethical clearance from NHS Research Ethics Committees.
: The authors declare that they have no conflict of interest.
: UCL Institute of Education provided ethical approval for the secondary analysis used in this manuscript.