Received: 5 January 2018
Accepted: 20 February 2019
First Online: 4 March 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Tzu Chi Medical Center (REC No.: IRB104-131C). The requirement for participant consent was waived owing to the retrospective nature of this study using de-identified secondary data.
: Not applicable.
: The authors declare that they have no competing interests.
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