- Correspondence to Dr Ding Ding, Prevention Research Collaboration, Sydney School of Public Health, (6N55) Level 6, the Charles Perkins Centre (D17), The University of Sydney, Camperdown, NSW 2006, Australia;
- Accepted 10 March 2017
- Published in print 1 October 2017.
- Published online 18 September 2017.
- Published first 26 April 2017.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.