[1] Univ Barcelona, Resp Inst, Hosp Clin, IDIBAPS, Barcelona, Spain
[2] CIBER Enfermedades Resp CIBERES, Madrid, Spain
[3] Univ Amsterdam, Dept Resp Med, Acad Med Ctr, Amsterdam, Netherlands
[4] Univ Southampton, Primary Care & Populat Sci, Southampton, Hants, England
[5] Univ Marburg, Univ Med Ctr Giessen & Marburg, Dept Med Pulm & Crit Care Med, D-35032 Marburg, Germany
[6] German Ctr Lung Res DZL, Hannover, Germany
[7] Ghent Univ Hosp, Dept Resp Med, Ghent, Belgium
[8] Erasmus MC, Dept Epidemiol & Resp Med, Rotterdam, Netherlands
[9] Univ Southampton, Dept Clin & Expt Sci, Fac Med, Southampton Gen Hosp, Southampton, Hants, England
[10] Univ Paris 11, Serv Pneumol, Hop Bicetre, AP HP,INSERM,UMR S 999, Le Kremlin Bicetre, France
[11] St Georges Univ London, London, England
[12] Univ Newcastle, Hunter Med Res Inst, John Hunter Hosp, Dept Resp & Sleep Med, Callaghan, NSW 2308, Australia
[13] Univ Newcastle, Prior Res Ctr Asthma & Resp Dis, Callaghan, NSW 2308, Australia
[14] Univ Hosp South Manchester NHS Fdn Trust, Ctr Resp Med & Allergy, Manchester Acad Hlth Sci Ctr, Manchester, Lancs, England
[15] Med Res Inst New Zealand, Wellington, New Zealand
[16] Univ Oxford, Resp Med Unit, Nuffield Dept Med, NDM Res Bldg, Oxford, England