Received: 17 October 2019
Accepted: 11 September 2020
First Online: 18 September 2020
Ethics approval and consent to participate
: This study was approved and consent to participate was waived by Research Ethics Committee (REC) of Hong Kong Sanatorium & Hospital under the reference number RC-2019-21. No patient-identifying data was collected.
: Not applicable.
: The authors declare that they have no competing interests.