Text and Data Mining valid from 2020-01-09
Received: 1 September 2019
Accepted: 31 December 2019
First Online: 9 January 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board (IRB) of the China Medical University and Hospital (CMUH) Research Ethics Committee (REC) (IRB permit number: CMUH-104-REC2–115). Consent to participate was waived because this study was a retrospective database analysis.
: Not applicable.
: The authors declare that they have no competing interests.