Zhang, Bo
Yan, Xiangyu
Li, Yongjie
Zhu, He
Liu, Zhimin
Lu, Zuhong
Jia, Zhongwei http://orcid.org/0000-0002-5362-7339
Funding for this research was provided by:
National Natural Science Foundation of China (91546203, 91846302)
Ministry of Public Security of the People's Republic of China (0716-1541GA590508)
Ministry of Science and Technology of the People’s Republic of China (2020YFC0849200)
Beijing Advanced Discipline Construction Project (BMU2019GJJXK005)
Article History
Received: 13 January 2021
Accepted: 7 June 2021
First Online: 12 June 2021
Declarations
:
: This study is a secondary data analysis. The data we have were anonymized by the government to protect the privacy of persons who use drugs, and this study did not access any individually identifiable data, and thus ethical approval was waived by Peking University Institutional Review Board.
: Not applicable.
: None.