Received: 19 September 2019
Accepted: 28 November 2019
First Online: 9 December 2019
Ethics approval and consent to participate
: The study protocol was approved by the institutional review board of Taoyuan branch of Chang Gung Memorial Hospital as 105-1130D. Due to the retrospective design of the study, the local ethic committee confirmed that informed consent was not necessary from participants.
: Not applicable.
: The authors declare that they have no competing interests.