Received: 30 April 2018
Accepted: 9 August 2018
First Online: 29 August 2018
Ethics approval and consent to participate
: The study was approved by the Chang Gung Memorial Hospital (CGMH) Institutional Review Board and was exempted from requiring informed consent and full committee review.
: This study was a retrospective cohort study. Thus, obtaining consent from a patient was waived by the institutional review board.
: The authors declare that they have no competing interests.
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