[1] Stavanger Univ Hosp, Dept Paediat, Stavanger, Norway
[2] Univ Stavanger, Fac Hlth Sci, Stavanger, Norway
[3] Stavanger Univ Hosp, Dept Clin Neurophysiol, Stavanger, Norway
[4] Karolinska Univ Hosp, Astrid Lindgren Childrens Hosp, Dept Neonatol, Stockholm, Sweden
[5] Karolinska Inst, Dept Clin Sci Intervent & Technol, Stockholm, Sweden
[6] Skane Univ Hosp, Lund Malmo NIDCAP Training & Res Ctr, Dept Neonatol, Lund, Sweden
[7] Stavanger Univ Hosp, Dept Biostat, Stavanger, Norway
[8] Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden