[1] Univ Gothenburg, Inst Clin Sci, Sahlgrenska Acad, Dept Pediat, Gothenburg, Sweden
[2] Sahlgrens Univ Hosp, Dept Pediat, Reg Vastra Gotaland, Gothenburg, Sweden
[3] Cty Council Varmland, Ctr Clin Res & Educ, Varmland, Sweden
[4] Orebro Univ, Sch Med Sci, Orebro, Sweden
[5] Blekinge Hosp, Pediat Clin, Karlskrona, Sweden