1. Department of Social Work, The Chinese University of Hong Kong, Hong Kong, China
2. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
3. Department of Health Sciences, University of Central Florida, Orlando, FL, USA
4. Rory Meyers College of Nursing, New York University, New York, NY, USA
5. Department of Political Science, Statistics, and School of Education, Iowa State University, Ames, IA, USA