Funding for this research was provided by:
Natural Science Foundation of Shaanxi Province (2016KTCL03-07)
Received: 6 May 2020
Accepted: 6 September 2020
First Online: 14 September 2020
Ethics approval and consent to participate
: The retrospective design and study were submitted and approved by the Medical Ethics Committee of the Second Affiliated Hospital of Xi’an Jiaotong University. The requirements for informed consent of patients were waived because the study did not interfere with patient care or a breach of patient privacy.
: Not applicable.
: The authors declare that they have no competing interests.