Funding for this research was provided by:
National Natural Science Foundation of China (81672644)
Received: 10 March 2019
Accepted: 13 June 2019
First Online: 25 June 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Shengjing Hospital of China Medical University. The requirement for informed consent was waived given the retrospective nature of the data, which was approved by the Ethics Committee of Shengjing Hospital of China Medical University.
: Not applicable.
: The authors declare that they have no competing interests.