1. St Vincent's Clinical School; Faculty of Medicine; University of New South Wales; Sydney; Australia
2. Department of Otorhinolaryngology; St Vincent's Hospital; Sydney; Australia
3. Sydney School of Public Health; University of Sydney; Sydney; Australia
4. Department of Otolaryngology; Concord Repatriation General Hospital; Sydney; Australia
5. Department of Anatomical Pathology; St Vincent's Hospital; Sydney; Australia