[1] Erasmus Univ, Dept Pediat Resp Med, Rotterdam, Netherlands
[2] Natl Inst Publ Hlth & Environm, Dept Chron Dis Epidemiol & Infect Dis, NL-3720 BA Bilthoven, Netherlands
[3] Univ Utrecht, Inst Risk Assessment Sci, Utrecht, Netherlands
[4] Univ Utrecht, Julius Ctr Hlth Sci & Primary Sci, Med Ctr, Utrecht, Netherlands
[5] Univ Groningen, Dept Epidemiol, Med Ctr, Groningen, Netherlands
[6] Wilhelmina Childrens Hosp, Ctr Pediat Allergol, Utrecht, Netherlands
[7] Univ Groningen, Med Ctr, Beatrix Childrens Hosp, Groningen, Netherlands