Benjamin, Caroline
Houghton, Catherine
Foo, Claire
Edgar, Chris
Mannion, Gail
Birch, Jan
Ellis, Ian
Weber, Astrid
Article History
Received: 7 October 2014
Revised: 2 January 2015
Accepted: 20 January 2015
First Online: 11 March 2015
Change Date: 16 July 2015
Change Type: Correction
Change Details: This paper has been amended since online publication and a corrigendum also appears in this issue
Competing interests
: The authors declare no conflict of interest.
Free to read: This content has been made available to all.