[1] Hosp del Mar, IMIM, Dept Nephrol, Barcelona 08003, Spain
[2] Univ Sydney, Sydney Sch Publ Hlth, Sydney, NSW 2006, Australia
[3] Univ Sydney, Westmead Millennium Inst, Ctr Transplant & Renal Res, Westmead, NSW 2145, Australia
[4] Childrens Hosp Westmead, Ctr Kidney Res, Cochrane Renal Grp, Westmead, NSW, Australia
[5] Hosp Ramon & Cajal, CIBERESP, E-28034 Madrid, Spain
[6] Hosp Ramon & Cajal, Unidad Bioestadist, E-28034 Madrid, Spain
[7] CIBER Epidemiol & Publ Hlth CIBERESP, Ramon Y Cajal Inst Hlth Res IRYCIS, Clin Biostat Unit, Madrid, Spain
[8] Cochrane Collaborating Ctr, Madrid, Spain
[9] CIBERESP, Madrid, Spain