Received: 15 April 2018
Accepted: 14 January 2019
First Online: 8 February 2019
Ethics approval and consent to participate
: The study has been approved by the ethics committees of the Hong Kong Polytechnic University, Hong Kong; Central Cluster of the Hospital Authority, Hong Kong; The National University Hospital; Singapore; The University of Manchester, Manchester, UK; and the Central Manchester Research and Ethics Committee. All participants have provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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