Funding for this research was provided by:
Natural Science Foundation of Shanghai (17ZR1401400)
Ministry of Education of the People's Republic of China (20120071120050)
National Natural Science Foundation of China (81772170, 81502870)
Text and Data Mining valid from 2018-12-01
Received: 18 October 2017
Accepted: 23 November 2018
First Online: 27 December 2018
Ethics approval and consent to participate
: This study was undertaken with the retrospective analysis of data collected from the Chinese Public Health Science Data Center, and the data used in the analysis were anonymized and no additional contact was made with patients to obtain further information as a part of this study, therefore, no ethical approval was required.
: Not applicable.
: The authors declare that they have no competing interests.
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