Kong, Hao
Li, Nan
Tian, Jie
Li, Xue‐Ying
Article History
Accepted: 13 July 2020
First Online: 20 July 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interests.
: Because of the retrospective and observational nature of the study, the local Ethics Committee agreed to exempt written informed consent.
: The original study protocol was approved by the Clinical Research Ethics Committee of Peking University First Hospital, Beijing, China (2019 [47]) on July 24, 2019.