1. Department of Psychological Medicine, The University of Auckland, Auckland, New Zealand
2. Pain Service, Northland District Health Board, Northland, New Zealand
3. Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
4. The Auckland Regional Pain Service, Auckland District Health Board, Auckland, New Zealand
5. Chronic Pain Service, Department of Anaesthesia and Perioperative Medicine, Waitemata District Health Board, Auckland, New Zealand