1. and 6 Consultants,
2. Research Fellow, 5 Director,
3. Resident,
4. Consultant, Department of Otolaryngology, City of Vienna Hospital Lainz, Wolkerbergenstraße 1, A‐1130 Vienna, Austria,
5. Professor, Department of Anaesthesia and Intensive Care Medicine,
6. Research Director, Ludwig Boltzmann Institute for Economics of Medicine in Anaesthesia and Intensive Care