1. Department of Maternal, Child & Adolescent Health, School of Public Health, Anhui Medical University, Hefei, Anhui Province, China;
2. Centre for Adolescent Health,
3. Clinical Epidemiology and Biostatistics Unit, and
4. Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia; and
5. Centre for Community Health, Murdoch Childrens Research Institute, Royal Children’s Hospital, Parkville, Victoria, Australia;
6. Department of Paediatrics and the Liggins Institute, The University of Auckland, Auckland, New Zealand