[1] UCL Great Ormond St Inst Child Hlth, Physiotherapy, London, England
[2] Dalhousie Univ Halifax, Community Hlth & Epidemiol, Halifax, NS, Canada
[3] Great Ormond St Hosp Sick Children, Paediat Cyst Fibrosis Unit, London, England
[4] Barts Hlth NHS Trust, Royal London Hosp, Paediat Cyst Fibrosis Ctr, London, England
[5] Royal Brompton & Harefield NHS Fdn Trust, Paediat Cyst Fibrosis Unit, London, England
[6] UCL GOS Inst Child Hlth, Physiotherapy, 30 Guilford St, London WC1N 1EH, England