[1] Lund Univ, Dept Clin Sci, Lund, Sweden
[2] Vrinnevi Hosp, Dept Paediat, Norrkoping, Sweden
[3] Umea Univ, Dept Epidemiol & Global Hlth, Umea, Sweden
[4] Karolinska Univ Hosp, Dept Med, Clin Epidemiol, Stockholm, Sweden
[5] Lund Univ, Dept Clin Sci Malmo, Lund, Sweden
[6] Skane Univ Hosp, Dept Paediat, Malmo, Sweden
[7] Univ Gothenburg, Sahlgrenska Acad, Inst Clin Sci, Dept Paediat, Gothenburg, Sweden
[8] Sahlgrens Univ Hosp, Queen Silvia Childrens Hosp, Gothenburg, Sweden
[9] Linkoping Univ, Div Paediat, Dept Biomed & Clin Sci, Linkoping, Sweden
[10] Cty Hosp Ryhov, Dept Paediat, Jonkoping, Sweden
[11] Linkoping Univ Hosp, Crown Princess Victoria Childrens Hosp, Linkoping, Sweden