Text and Data Mining valid from 2019-09-18
Received: 5 December 2018
Accepted: 4 September 2019
First Online: 18 September 2019
Ethics approval and consent to participate
: Ethical approval for this study was obtained from the ethical committee of St. Marianna University. The institutional review board at our facility approved this retrospective study and waived the need for written consent.
: Not applicable.
: The authors declare that they have no competing interests.