Received: 18 June 2019
Accepted: 19 December 2019
First Online: 30 December 2019
Ethics approval and consent to participate
: The research involving patient data described in this paper were approved by the City University of Hong Kong Review Board. (IRB number: 3-2-201803_02). All participants gave their written informed consent.
: Not Applicable.
: The authors declare that they have no competing interests.