Received: 5 October 2020
Accepted: 10 November 2020
First Online: 18 November 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Ethics Committees of Yokohama City University Medical Centre (approval no. B170900003). The approving authority for data access was the Japanese Association for the Surgery of Trauma (Trauma Registry Committee). The need for consent to individual participate was waived by the Institutional Ethics Committees that approved our study due to the observational nature of the study design.
: Not applicable.
: The authors declare that they have no competing interests.