Received: 29 August 2019
Accepted: 7 November 2019
First Online: 15 November 2019
Ethics approval and consent to participate
: The retrospectivestudy was approved by the Institutional Review Board (IRB) of Chang Gung Medical Foundation and written informed consent was waived (No 201900354B0).
: Not applicable.
: The authors declare that they have no competing interests.