1. 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. Institute for Social Medicine, Epidemiology and Health Economics Charité – Universitätsmedizin Berlin Berlin Germany
4. Department of Pediatrics Technical University of Munich Munich Germany
5. Department of Pediatrics, Allergy Working Group University Clinic Freiburg Freiburg Germany
6. Department of Pediatrics and Adolescent Medicine University Medicine Mainz Mainz Germany
7. Department of Pediatrics Heinrich‐Heine‐University Düsseldorf Germany
8. Institute of Clinical Epidemiology and Biometry University of Würzburg Würzburg Germany
9. State Institute of Health Bavarian Health and Food Safety Authority Erlangen Germany