Received: 24 April 2018
Accepted: 30 April 2019
First Online: 13 May 2019
Ethics approval and consent to participate
: This retrospective study was approved by Chang Gung Medical Foundation Institutional Review Board (IRB No. 201800534B0), where the need of informed consent to participate was waived. Nevertheless, the participants were still informed about purpose of the clinical study with verbal consent to participate in this study.
: Not applicable.
: The authors declare that they have no competing interests with respect to the research, authorship or publication of the article.
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