[1] Univ Hull, Hull York Med Sch, Resp Res Grp, Kingston Upon Hull, N Humberside, England
[2] Univ Gothenburg, Sahlgrenska Univ Hosp, Dept Internal Med Resp Med & Allergol, Gothenburg, Sweden
[3] Lithuanian Univ Hlth Sci, Dept Pulmonol, Kaunas, Lithuania
[4] Kings Coll London, Fac Life Sci & Med, Ctr Human & Appl Physiol Sci, Sch Basic & Med Biosci, London, England
[5] Kings Coll Hosp London, Dept Resp Med, London, England
[6] Montefiore Med Ctr, Albert Einstein Coll Med, Bronx, NY 10467 USA
[7] Univ Autonoma Barcelona, Dept Med, Pulm Serv, Corp Sanitaria Parc Tauli Sabadell, Barcelona, Spain
[8] Univ Glasgow, MRC CSO Social & Publ Hlth Sci Unit, Glasgow, Lanark, Scotland
[9] Univ & Res Hosp, Pediat Cough & Asthma Ctr, Ist Osped Bergamaschi, Bergamo, Italy
[10] Guangzhou Med Univ, Guangzhou Inst Resp Hlth, Dept Clin Res, State Key Lab Resp Dis,Affiliated Hosp 1, Guangzhou, Guangdong, Peoples R China
[11] Queens Univ Belfast, Ctr Expt Med, Sch Med Dent & Biomed Sci, Belfast, Antrim, North Ireland
[12] Iberoamer Cochrane Ctr, Barcelona, Spain
[13] McMaster Univ, Dept Med, Div Respirol, Hamilton, ON, Canada
[14] Univ Manchester, Manchester Acad Hlth Sci Ctr, Div Infect Immun & Resp Med, Manchester, Lancs, England
[15] Univ Manchester, Manchester Univ NHS Fdn Trust, Div Infect Immun & Resp Med, Manchester, Lancs, England
[16] Univ Ulsan, Asan Med Ctr, Dept Allergy & Clin Immunol, Airway Sensat & Cough Res Lab,Coll Med, Seoul, South Korea
[17] Univ Bern, Bern, Switzerland
[18] Hoestpoli Isala Hosp, Dept Resp Med, Zwolle, Netherlands
[19] Erasmus Univ, Dept Resp Med, Med Ctr, Rotterdam, Netherlands
[20] Univ Vienna, Wilhelminen Hosp, Dept Pediat, Teaching Hosp, Vienna, Austria