Received: 20 November 2019
Accepted: 6 September 2020
First Online: 22 September 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of the Affliated Hospital of Xuzhou Medical College (Xuzhou, China). Medical department granted permission to access and use the medical records described in this study. Signed informed consents were obtained from the patients or guardians prior to the study.
: Not applicable.
: The authors declare that they have no competing interests.