Abu Saleh M Abdullah1,2
, Tai-Hing Lam2
, Steve KK Chan2
, Gabriel M Leung2
, Iris Chi3
, Winnie WN Ho2,5
and Sophia SC Chan4 
1Department of International Health, Boston University School of Public Health, Boston, Massachusetts, USA
2Department of Community Medicine, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
3School of Social Work, University of Southern California, Los Angela, USA
4Department of Nursing Studies, Li Ka Sing Faculty of Medicine, The University of Hong Kong, Hong Kong, PR China
5Department of Social Work, Hong Kong Baptist University, Hong Kong, PR China