Text and Data Mining valid from 2020-04-21
Received: 1 October 2019
Accepted: 13 April 2020
First Online: 21 April 2020
Ethics approval and consent to participate
: We obtained ethical approval from the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW17–510). Informed consent was received in electronic from each participant.
: Not applicable.
: The authors declare that they have no competing interests.