[1] INSAF Resp Res Inst, Wiesbaden, Germany
[2] Univ Hosp South Manchester, Wythenshawe Hosp, North West Interstitial Lung Dis Unit, Manchester, Lancs, England
[3] Univ Manchester, Manchester Acad Hlth Sci Ctr, Manchester, Lancs, England
[4] Penn State Univ, Dept Med & Pediat, State Coll, PA USA
[5] Univ Toronto, Dept Family & Community Med, Toronto, ON, Canada
[6] Observat & Pragmat Res Inst, Primary Care Resp Res, Singapore, Singapore
[7] Family Phys Airways Grp Canada, Toronto, ON, Canada
[8] Cork Univ Hosp, Dept Resp Med, Cork, Ireland
[9] Univ Coll Cork, Cork, Ireland