1. The Department of Pediatrics, Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine Charité—Universitätsmedizin Berlin Berlin Germany
2. L'altrastatistica srl, Consultancy & Training, Biostatistics office Rome Italy
3. The Division of Immunopathology, Department of Pathophysiology and Allergy Research, Centre of Pathophysiology, Infectiology and Immunology Medical University of Vienna Wien Austria
4. The Institute for Social Medicine, Epidemiology and Health Economics Charité—Universitätsmedizin Berlin Berlin Germany
5. The Department of Pediatrics Technical University of Munich Munich Germany
6. The Department of Pediatrics, Allergy Working Group University Clinic Freiburg Freiburg Germany
7. The Department of Pediatrics and Adolescent Medicine University Medicine Mainz Mainz Germany
8. The Department of Pediatrics Heinrich‐Heine‐University Düsseldorf Germany
9. The Institute of Clinical Epidemiology and Biometry University of Würzburg Würzburg Germany
10. The State Institute of Health, Bavarian Health and Food Safety Authority Bad Kissingen Germany