1. External Evaluation Unit, University of Helsinki & Helsinki University Hospital, University of Eastern Finland, Finland
2. Hospital District of Helsinki and Uusimaa, External Evaluation Unit, Tynnyrintekijänkatu 1 C, Helsinki, Finland
3. Department of Otorhinolaryngology – Head & Neck Surgery, University of Helsinki & Helsinki University Hospital, Finland
4. External Evaluation Unit, University of Helsinki & Helsinki University Hospital, Finland