Meng, Zhaolin
Zhu, Min
Cai, Yuanyi
Cao, Xiaohong
Wu, Huazhang
Article History
Received: 29 September 2018
Accepted: 28 March 2019
First Online: 16 April 2019
Ethics approval and consent to participate
: The Ethics Committee of China Medical University approved the study protocol. This analysis used secondary data, and the authors did not require direct contact with participants, thus consent to participate was waived.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.