[1] Leeds Teaching Hosp NHS Trust, Leeds Gen Infirm, Reg Paediat CF Unit, Leeds LS2 9NS, W Yorkshire, England
[2] Univ Cent Lancashire, Sch Psychol, Preston PR1 2HE, Lancs, England
[3] Liverpool Heart & Chest Hosp, Adult Cyst Fibrosis Unit, Liverpool, Merseyside, England
[4] Univ Cent Lancashire, Sch Hlth, Preston PR1 2HE, Lancs, England
[5] Univ Miami, Child Div, Miami, FL USA
[6] Univ Leeds, Sch Med, Inst Hlth Sci, Leeds LS2 9JT, W Yorkshire, England