[1] Univ Melbourne, Melbourne, Vic, Australia
[2] Murdoch Childrens Res Inst, Melbourne, Vic, Australia
[3] Murdoch Childrens Res Inst, Clin Epidemiol & Biostat Unit, Melbourne, Vic, Australia
[4] La Trobe Univ, Dept Math & Stat, Melbourne, Vic, Australia
[5] Royal Childrens Hosp, Dept Cardiac Surg, Melbourne, Vic 3052, Australia
[6] Royal Childrens Hosp, Dept Cardiol, Melbourne, Vic 3052, Australia
[7] Univ Melbourne, Dept Pediat, Melbourne, Vic, Australia