Received: 8 March 2018
Accepted: 4 July 2019
First Online: 17 July 2019
Ethics approval and consent to participate
: This retrospective study was approved by the Research Ethics Committee of NTUH (Institutional Review Board No: 20160613132RIND), and informed consent was waived for this analysis based on approval by the Research Ethic Committee, as the data were analyzed anonymously.
: Not applicable.
: The authors declare that they have no competing interests.