Received: 19 May 2021
Accepted: 13 August 2021
First Online: 21 August 2021
: The Ethics Committee of Kitakyushu City Hospital Organization approved the study protocol. Given the retrospective design and the assurance of anonymity, the requirement of obtaining patient consent was waived by the Ethics Committee of Kitakyushu City Hospital Organization. Information about study participation was officially announced using posters. All patient data were anonymized prior to the analysis.
: Not applicable.
: The authors declare that they have no competing interests.