Funding for this research was provided by:
Innovative Research Group Project of the National Natural Science Foundation of China
Received: 22 January 2020
Revised: 31 May 2020
Accepted: 21 July 2020
First Online: 4 August 2020
Compliance with ethical standards
: The scientific guarantor of this publication is Jin Wei Qiang.
: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
: One of the authors has significant statistical expertise.
: Written informed consent was not required for this study because of the retrospective nature of the study.
: Local institutional Review Board approval was obtained.
: • retrospective• diagnostic study• multicenter study