Funding for this research was provided by:
International Science and Technology Cooperation and Exchange Program of Shaanxi Province (2015KW-045)
Received: 19 December 2018
Accepted: 25 October 2019
First Online: 21 November 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of The First Affiliated Hospital of Xi’an Jiaotong University. Based on the approval of Ethics Committee of the First Affiliated Hospital of Xi’an Jiaotong University, the informed consents obtained from the patients was verbal due to there was no health damage or information exposure to the participants in this retrospective study; and for patients ≤16, we directly communicated with the guardian over the phone and obtained their consent.
: Not applicable.
: The authors declare that they have no competing interests.