Ma, Qiuyue
Yang, Fude
Ma, Botao
Jing, Wenzhan
Liu, Jue
Guo, Moning
Li, Juan
Wang, Zhiren
Liu, Min http://orcid.org/0000-0002-5059-3743
Funding for this research was provided by:
National Natural Science Foundation of China (71874003, 81703240)
Article History
Received: 4 November 2020
Accepted: 26 December 2020
First Online: 29 January 2021
Compliance with ethical standards
:
: The authors have no competing interests to declare.
: The study used information that is available in database of the Beijing Municipal Commission of Health and Family Planning Information Center, and all identifiable information was removed. Patients and the public were not involved in the design and conduct of the study. But the study findings will be disseminated through multiple channels including publication, meetings, conferences and social media.