Wu, Chenyao
Zhang, Baiyang
Dai, Zhen
Zheng, Qianwen
Duan, Zhenhua
He, Qinying
Zhu, Cairong
Article History
Received: 27 July 2020
Accepted: 7 March 2021
First Online: 8 April 2021
Declarations
:
: This study was considered to be a policy evaluation research and didn’t require research ethical approval by the Ethics Committee. We inquired IRB of Sichuan University and the board suggested ethics approval be waived given that all data have been completely deidentified and aggregated before access and analysis. All the data used in the study were collected with permission and in accordance with national regulation by Chengdu Center for Disease Control and Prevention.
: Not applicable.
: The authors declare that they have no competing interests.