[1] Univ Groningen, Univ Med Ctr Groningen, Dept Gen Practice, NL-9700 RB Groningen, Netherlands
[2] Univ Groningen, Univ Med Ctr Groningen, Dept Pediat, Div Pediat Pulmonol & Pediat Allergy, NL-9700 RB Groningen, Netherlands
[3] Univ Groningen, Univ Med Ctr Groningen, GRIAC Res Inst, NL-9700 RB Groningen, Netherlands