1. Department of Otolaryngology - Head and Neck Surgery; University of Ottawa; Ottawa Canada
2. Clinical Epidemiology Program; Ottawa Hospital Research Institute; Ottawa Canada
3. Department of Epidemiology; Erasmus University Medical Center Rotterdam; Rotterdam Netherlands
4. Institut for Klinisk Medicin; Aarhus University; Aarhus Denmark
5. Department of Pathology and Laboratory Medicine; Dalhousie University; Halifax Canada
6. Endocrinology and Metabolism; University of Ottawa; Ottawa Canada
7. Department of Neurosurgery; University of Ottawa; Ottawa Canada
8. Institute of General Practice; Medical Faculty of the Heinrich-Heine University; Düsseldorf Germany
9. Department of Epidemiology and Biostatistics and Department of Radiology and Nuclear Medicine; Erasmus University Medical Center Rotterdam; Rotterdam Netherlands
10. Center for Health Decision Sciences; Harvard T.H. Chan School of Public Health, Boston; Boston Massachussetts USA