[1] Pte Ltd, Observat & Pragmat Res Inst, 60 Paya Lebar Rd,Paya Lebar Sq,Level 5, Singapore 409051, Singapore
[2] Univ Aberdeen, Acad Primary Care, Aberdeen, Scotland
[3] Inhalat Consultancy Ltd, Leeds, W Yorkshire, England
[4] Natl Jewish Hlth, Dept Med, Denver, CO USA
[5] Univ Colorado, Denver, CO 80202 USA
[6] Brigham & Womens Hosp, Pulm & Crit Care Div, 75 Francis St, Boston, MA 02115 USA
[7] Harvard Med Sch, Boston, MA 02115 USA
[8] Emma Childrens Hosp AMC, Dept Pediat Resp Med & Allergy, Amsterdam, Netherlands
[9] Univ Ferrara, Dept Med Sci, Ferrara, Italy
[10] Imperial Coll London, Airway Dis Sect, Natl Heart & Lung Inst, London, England
[11] Royal Brompton Hosp, London, England
[12] Univ Paris 05, Cochin Hosp Grp, AP HP, EA2511, Paris, France