Funding for this research was provided by:
National Natural Science Foundation of China (71203003)
Beijing Health Development Research Project (2014-3-4111)
Received: 7 May 2019
Accepted: 22 October 2019
First Online: 14 November 2019
Ethics approval and consent to participate
: The project proposal was reviewed and approved by the Ethics Committee of Peking University Sixth Hospital, and all peers and consumers provided written informed consents.
: Not applicable.
: The authors declare that they have no competing interests.