1. Center for Congenital Heart DiseasesDepartment of Pediatric CardiologyBeatrix Children's HospitalUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
2. College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
3. Department of EpidemiologyUniversity Medical Center GroningenUniversity of GroningenGroningenThe Netherlands
4. Children's Hospital ColoradoAuroraColoradoUSA