Text and Data Mining valid from 2019-08-05
Received: 1 April 2019
Accepted: 25 July 2019
First Online: 5 August 2019
Ethics approval and consent to participate
: This study was approved by the Ethical Committee of China Medical University Hospital (CMUH108-REC3–063). Consent to participate was not applicable due to the retrospective nature of this study.
: Not applicable.
: The authors declare that they have no competing interests.