1. Department of Clinical Epidemiology & Biostatistics, McMaster University, Hamilton, Ontario, Canada
2. Redwood Outcomes, Vancouver, British Columbia, Canada
3. School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
4. Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
5. Pfizer Ltd, New York, New York, USA
6. Department of Evaluation and Treatment of Pain, Clinical Neuroscience Federation, La Timone Hospital, Marseille, France
7. Neurology Department, Alfred Hospital, Melbourne, Victoria, Australia
8. Department of Medicine, Monash University, Melbourne, Victoria, Australia
9. NIHR-Wellcome Trust Clinical Research Facility, King’s College London, London, UK