1. Institute of Medical Statistics, Informatics and Epidemiology, Medical Faculty, University of Cologne, Cologne, Germany
2. CRI – Clinical Research International Limited, Hamburg, Germany
3. MSD SHARP & DOHME GMBH, Haar, Germany
4. Clinical Trials Center Cologne, Medical Faculty, University of Cologne, Cologne, Germany
5. Allergy & Respiratory Diseases, Department of Internal Medicine, University of Genoa, Genoa, Italy