1. Health and Rehabilitation Research Institute; Auckland University of Technology; Auckland New Zealand
2. Waitemata Pain Service; Department of Anaesthesiology and Perioperative Medicine; North Shore Hospital; Auckland New Zealand
3. Centre for Cerebral and Cardiovascular Disease Information; National Cerebral and Cardiovascular Centre; Osaka Japan
4. Channing Division of Network Medicine; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
5. Department of Twin Research and Genetic Epidemiology; King's College London; London UK