Funding for this research was provided by:
Jiangsu Provincial Commission of Health and Family Planning (LGY 2017083)
Jiangsu Health International Exchange Program
Received: 24 September 2020
Accepted: 2 January 2021
First Online: 19 January 2021
Ethics approval and consent to participate
: We performed analysis on routine administrative data and no ethical approval was required.
: We performed analysis on routine administrative data, consent for publication is not applicable.
: Sheng-Lan Tang is the deputy Editor-in-Chief of the journal Infectious Diseases of Poverty. He was not involved in the peer-review or handling of the manuscript. The authors have no other competing interests to disclose.