Funding for this research was provided by:
Japan Society for the Promotion of Science (18H00428)
Japan Agency for Medical Research and Development (JP18dk0207027h0003)
Received: 23 April 2019
Accepted: 29 July 2019
First Online: 2 September 2019
Ethics approval and consent to participate
: This research was conducted with approval from the Chiba University Graduate School of Medical Research Institute Ethics Review Committee (approval number 3090). Informed consent was formally waived by the Medical Research Institute Ethics Review Committee as data were collected from medical records and patients were not contacted. However, due to Japanese Ethical Guidelines, we displayed a poster in the waiting room of the hospital that consisted of the information regarding the collection and use of data for this study, and guaranteed the protection of personal information.
: Not applicable.
: The authors declare that they have no competing interests.