Text and Data Mining valid from 2019-08-28
Received: 12 June 2019
Accepted: 15 August 2019
First Online: 28 August 2019
Ethics approval and consent to participate
: The study was approved by the institutional review board of the Tokyo Bay Urayasu Ichikawa Medical Center (ID: 247). The requirement for informed consent was waived because the study was retrospective and patient information was anonymized and de-identified prior to analysis.
: Not applicable. This study was a retrospective study that used data obtained from medical records.
: The authors declare that they have no competing interests.