Wang, Meijian
Hou, Xinguo
Hu, Wenchao
Chen, Li
Chen, Shihong
Article History
Received: 9 July 2018
Accepted: 26 February 2019
First Online: 4 March 2019
Ethics approval and consent to participate
: The ethics committee of Qilu Hospital of Shandong University approved the study. Written informed consent was obtained from each participant before data collection.
: Not applicable.
: The authors declare that they have no competing interest.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.