[1] Imperial Coll London, Royal Brompton Hosp, Natl Heart & Lung Inst, Fac Med, London, England
[2] Univ Auckland, Starship Childrens Hlth & Kidz Hosp 1, Fac Med & Hlth Sci, Dept Paediat Child & Youth Hlth, Auckland, New Zealand
[3] Chinese Univ Hong Kong, Dept Paediat, Hong Kong, Peoples R China
[4] Queensland Univ Technol, Fac Hlth, Sch Publ Hlth & Social Work, Brisbane & Menzies Sch Hlth Res, Darwin, Australia
[5] Univ Sao Paulo, Hosp das Clin HCFMUSP, Fac Med, Inst do Coracao InCor, Sao Paulo, Brazil
[6] Univ Liverpool, Dept Womens & Childrens Hlth, Liverpool, England
[7] Columbia Univ, Dept Pediat & Environm Hlth Sci, Med Ctr, New York, NY USA
[8] Univ Washington, Dept Pediat, Sch Med, Seattle, WA USA
[9] Kalawati Saran Childrens Hosp, Lady Hardinge Med Coll, Dept Pediat, New Delhi, India
[10] Alder Hey Childrens NHS Fdn Trust, Liverpool, England
[11] Univ Cape Town, Red Cross War Mem Childrens Hosp, Dept Paediat & Child Hlth, Cape Town, South Africa
[12] Univ Cape Town, SA MRC Unit Child & Adolescent Hlth, Cape Town, South Africa