Received: 17 July 2018
Accepted: 25 September 2018
First Online: 17 October 2018
Ethics approval and consent to participate
: Patient data we used were acquired by a publicly available dataset that removed patient identifiers. The publicly available data were collected with patients’ informed consent approved by the institutional review boards of all participating institutions following 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The authors declare that they have no competing interests.
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