Received: 1 October 2018
Accepted: 19 December 2018
First Online: 1 February 2019
Ethics approval and consent to participate
: This study was approved by Kowloon East Cluster/ Kowloon Central Cluster Research Ethics Committee/Institutional Review Board of Hospital Authority of Hong Kong under the registration KC/KE-16-0084/ER-3. All study subjects gave written consent before recruitment. There was no reported adverse event from trial.
: Not applicable.
: The authors declare that they have no competing interests.
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