Funding for this research was provided by:
National Institute on Aging (OGHA 04034785; YA1323-08-CN-0020; Y1-AG-1005-01; R01-AG034479)
Shanghai Municipal Health Bureau (20174Y0147, 201840118)
Received: 2 July 2019
Accepted: 31 October 2019
First Online: 4 December 2019
Ethics approval and consent to participate
: SAGE was approved by the World Health Organization’s Ethical Review Board (RPC146), and local approval by the ethics review committee of the Chinese Center for Disease Control and Prevention (approval notice 200601). Each respondent signed informed consent.
: Not applicable.
: The authors declare that they have no competing interests.