Received: 27 May 2020
Accepted: 6 August 2020
First Online: 7 September 2020
Ethics approval and consent to participate
: This study was approved by The Joint Chinese University of Hong Kong – New Territories East Cluster Clinical Research Ethics Committee (2019.214) with waiver of informed consent because this was a retrospective study.
: Not applicable.
: The authors declare that they have no competing interests.