Text and Data Mining valid from 2019-08-14
Received: 5 February 2018
Accepted: 31 July 2019
First Online: 14 August 2019
Ethics approval and consent to participate
: The study protocol was approved by the Chi-Mei Medical Center institutional review board, and informed consent was waived based on the retrospective nature of this study.
: Not applicable
: The authors declare that they have no competing interests.