Bai, Huimin
Liu, Jun
Wang, Qiuxi
Feng, Ying
Lou, Tong
Wang, Shuzhen
Wang, Yue
Jin, Mulan
Zhang, Zhenyu
Article History
Received: 6 October 2017
Accepted: 17 April 2018
First Online: 24 April 2018
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of Beijing Chao-Yang Hospital, Affiliated China Capital Medical University. Participant consent was not necessary, as this study involved the use of a previously published de-identified database according to [details of national legislation].
: The authors declare that they have no competing interests.
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