1. Department of Paediatrics, Prince of Wales Hospital The Chinese University of Hong Kong Shatin Hong Kong
2. Hong Kong Hub of Paediatric Excellence The Chinese University of Hong Kong Shatin Hong Kong
3. General Practitioners Research Institute Groningen Netherlands
4. Groningen Research Institute Asthma and COPD (GRIAC), University Medical Center Groningen, University of Groningen Groningen Netherlands
5. Department of Pediatric Pulmonology and Pediatric Allergology, University Medical Center Groningen, Beatrix Children's Hospital, University of Groningen Groningen Netherlands