[1] Univ Med Ctr Rotterdam, Erasmus MC, Sophia Childrens Hosp, Div Neonatol,Dept Paediat, Rotterdam, Netherlands
[2] Univ Med Ctr Rotterdam, Erasmus MC, Dept Publ Hlth, Room NA 2401,POB 2040, NL-3000 CA Rotterdam, Netherlands
[3] Hungarian Acad Sci, Ctr Social Sci, Computat Social Sci Res Ctr Educ & Network Studie, Budapest, Hungary
[4] Corvinus Univ Budapest, Inst Sociol & Social Policy, Budapest, Hungary