He, Yingdong
Liu, Jing
Cai, Qingqing
Lv, Jicheng
Yu, Feng
Chen, Qian http://orcid.org/0000-0003-2508-4311
Zhao, Minghui
Article History
Received: 12 February 2018
Accepted: 14 June 2018
First Online: 19 July 2018
Compliance with ethical standards
:
: None of the authors received any support for this study. On behalf of all authors, the corresponding author states that there is no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical 433 standards.
: As this is a retrospective analysis, for this type of study formal consent is not required; informed consent for data collection, management and analysis was obtained from all individual participants included in the study.