1 Department of Pulmonary Diseases, Center of Excellence for Asthma, COPD and Respiratory Allergy, Franciscus Gasthuis and Vlietland, Rotterdam, Netherlands.
2 Department of Pulmonary Diseases, Erasmus Medical Centrum, Rotterdam, Netherlands.
3 Long Alliantie Nederland (LAN), Amersfoort, Netherlands.
4 Department of Pulmonary Diseases, Martini Hospital, Groningen, Netherlands.
5 Department of Pulmonary Diseases, Amsterdam University Medical Center, Amsterdam, Netherlands.
6 Coöperatie PreventPartner, Malden, Netherlands.
7 Polikliniek Mens en Arbeid, Amsterdam University Medical Center, Amsterdam, Netherlands.
8 General Practitioner, Maarssen, Netherlands.
9 National Heart and Lung Institute, Imperial College London; Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.