1Department of General Practice, University Medical Centre Nijmegen, Nijmegen, the Netherlands
2Department of Respiratory Medicine, University of Cape Town Lung Institute, Cape Town, South Africa
3Allergic Rhinitis and its Impact on Asthma, Service des Maladies Respiratoires, Hôpital Arnaud de Villeneuve, Montpellier Cédex 5, France
4GA2LEN is supported by EU framework programme for research, contract number FOOD-CT-2004-506378.
5Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
6School of Medicine, University of Washington, WA, USA
7COPD & Asthma Research Co-ordinator, Department of General Practice/Family Medicine, University Medical Centre Nijmegen, Nijmegen, the Netherlands
8Pediatrician, Pediatric Allergist, Turku Allergy Center, Turku, Finland
9First Affiliated Hospital, Guanghzou Canton, China