1 Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada L8S 4L8 reed.siemieniuk@medportal.ca.
2 Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
3 South Western Sydney Clinical School, UNSW, Australia.
4 Whitlam Orthopaedic Research Centre, Ingham Institute for Applied Medical Research, Liverpool, NSW 2170, Australia.
5 Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada L8S 4L8.
6 Division General Internal Medicine & Division of Clinical Epidemiology, University Hospitals of Geneva, CH-1211, Geneva, Switzerland.
7 Department of Orthopaedic Surgery, Joint Research, OLVG, 1090 HM Amsterdam, The Netherlands.
8 Faculty of Dentistry, Universidad de Chile, Independencia, Santiago, Chile.
9 Norwegian Institute of Public Health, Nydalen, N-0403 Oslo, Norway.
10 Department of Epidemiology and Preventive Medicine, School of Public Health & Preventive Medicine, Monash University, Melbourne, Vic 3004, Australia.
11 Monash Department of Clinical Epidemiology, Cabrini Institute; Suite 41 Cabrini Medical Centre, Malvern Vic, 3144, Australia.
12 Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden.
13 Oslo University Hospital, Blindern 0317 Oslo, Norway.
14 Richmond, Virginia, USA.
15 Clinical Effectiveness Research Group, Institute of Health and Society, University of Oslo, Blindern 0317 Oslo, Norway.
16 University Hospital North Norway, 9038 Tromso, Norway.
17 Department of Occupational Therapy, Physiotherapy and Radiography, Faculty of Health and Social sciences, Bergen University College, 5020 Bergen, Norway.
18 BMJ Editorial, BMA House, London WC1H 9JR, UK.
19 Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7HE, UK.
20 London, Ontario, Canada.
21 Ingersoll, Ontario, Canada N5C 3N1.
22 Department of Health and Science, University of Oslo, Oslo, Norway.
23 Department of Medicine, Hospital Innlandet Trust, Gjøvik, Norway.