Article History
Received: 24 February 2017
Accepted: 27 March 2018
First Online: 10 April 2018
Ethics approval and consent to participate
: This study had institutional ethical approval from the School of Medicine Ethics Committee, Cardiff University and all participants gave informed, written consent prior to participation.
: No individual data is included.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.