Text and Data Mining valid from 2019-06-17
Received: 13 November 2018
Accepted: 22 May 2019
First Online: 17 June 2019
Ethics approval and consent to participate
: The study received ethical approval from the University College London Research Ethics Committee (Ref 17.406). Written, informed consent was obtained from all participants.
: All participants provided written informed consent for their anonymized data to be used for publication with their identities protected with pseudonyms.
: The authors declare that they have no competing interests.