From the School of Sociology, Huazhong University of Science and Technology, Wuhan, China (Dr Cui); Department of Health Policy and Management, School of Public Health, Peking University Health Science Center, Beijing, China (Dr Huang, Mr Bai, Dr Guo); Center for Social Security Studies, Wuhan University, Wuhan, China (Dr Fu); and Sociologist and Independent Researcher, Islamabad, Pakistan (Ms Zia).

Conflicts of Interest: None declared.

Funding Sources: None declared.

Data Availability Statement: Data are available upon reasonable request.

Ethics Statements: The Ethics Committee of Peking University Medical Center approved this study (IRB00001052-22005). All participants were informed of the survey's purpose and their rights to decline their information. Also, electronic informed consent was obtained from these survey participants.

Supplemental digital contents are available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal’s Web site (www.joem.org).

Address correspondence to: Jing Guo, Department of Health Policy and Management, School of Public Health, Peking University Health Science Center, No. 38 Xue Yuan Rd, Haidian District, Beijing, China 100191 ([email protected]).