Text and Data Mining valid from 2018-06-21
Received: 23 April 2018
Accepted: 15 June 2018
First Online: 21 June 2018
Ethics approval and consent to participate
: This study was approved by the ethics committee of the Prince of Wales Hospital, The Chinese University of Hong Kong. All the participants provided written consent to participate in the study.
: Not applicable.
: The authors declare that they have no competing interests.
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