1. Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, LKS Faculty of Medicine , The University of Hong Kong , Hong Kong , P.R. China
2. Department of Paediatrics and Adolescent Medicine , Hong Kong Children’s Hospital , Hong Kong , P.R. China
3. Department of Paediatrics and Adolescent Medicine , Princess Margaret Hospital , Hong Kong , P.R. China
4. Department of Paediatrics and Adolescent Medicine , Tuen Mun Hospital , Hong Kong , P.R. China
5. Department of Paediatrics , Prince of Wales Hospital , Hong Kong , P.R. China
6. Department of Paediatrics , Queen Elizabeth Hospital , Hong Kong , P.R. China
7. Department of Paediatrics and Adolescent Medicine , United Christian Hospital , Hong Kong , P.R. China
8. Department of Paediatrics and Adolescent Medicine , Pamela Youde Nethersole Eastern Hospital , Hong Kong , P.R. China
9. Department of Paediatrics and Adolescent Medicine , Alice Ho Miu Ling Nethersole Hospital , Hong Kong , P.R. China
10. Department of Paediatrics , Kwong Wah Hospital , Hong Kong , P.R. China
11. Department of Paediatrics and Adolescent Medicine , Caritas Medical Centre , Hong Kong , P.R. China
12. Department of Paediatrics and Adolescent Medicine , Tseung Kwan O Hospital , Hong Kong , P.R. China