Received: 20 August 2020
Accepted: 22 December 2020
First Online: 8 January 2021
Ethics approval and consent to participate
: This study is approved by the Joint Chinese University of Hong Kong – New Territories East Cluster Clinical Research Ethics Committee (CREC 2020.106). For this type of retrospective study, formal consent is not required. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The authors declare that they have no competing interests.