Funding for this research was provided by:
China Medical Board (14-199)
Text and Data Mining valid from 2018-11-20
Received: 1 June 2018
Accepted: 28 October 2018
First Online: 20 November 2018
Ethics approval and consent to participate
: This study was approved by the ethics committee of West China School of Public Health, Sichuan University and the Human Research Ethics Committee of Curtin University. All participants have signed a consent form before enrollment to the study.
: Not applicable.
: The authors declare that they have no competing interests.
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