1. Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
2. Hellenic Society for Social Pediatrics and Health Promotion, Athens, Greece
3. Department of Pediatric Hematology-Oncology, “P&A Kyriakou” Children’s Hospital, Athens, Greece
4. Pediatric Hematology/Oncology Unit, First Department of Pediatrics, National and Kapodistrian University of Athens, “Agia Sofia” Children’s Hospital, Athens, Greece
5. Department of Pediatric Hematology-Oncology, “Agia Sofia” Children’s Hospital, Athens, Greece
6. Department of Pediatric Hematology and Oncology, Hippokration Hospital, Thessaloniki, Greece
7. Hematology-Oncology Unit, 2nd Pediatric Department, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece
8. Department of Pediatric Hematology-Oncology, University of Crete, Heraklion, Greece
9. Pediatric Hematology-Oncology Department, “Mitera” Children’s Hospital, Athens, Greece
10. Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece
11. Center for Evidence Synthesis in Health, Brown University School of Public Health, Providence, RI, USA