Funding for this research was provided by:
Hebei Province Science and Technology Support Program (17277728D)
Received: 24 October 2019
Accepted: 1 January 2020
First Online: 23 January 2020
: The authors declare that they have no conflict of interest.
: This research was approved by the Ethics Committee of Hebei General Hospital. It is a retrospective study without any identifiers related with patients. All patients participating in the study wrote informed consent.
: All patients in this study provided their consent for publication.