[1] Univ Alberta, Sch Publ Hlth, Dept Publ Hlth Sci, RTF 4075, Edmonton, AB T6G 2E1, Canada
[2] Univ Alberta, Sch Publ Hlth, Albert Ctr Injury Control & Res, Edmonton, AB T6G 2M7, Canada
[3] Univ Hawaii Manoa, John A Burns Sch Med, Dept Publ Hlth Sci, Honolulu, HI 96822 USA
[4] Toronto Western Hosp, Univ Hlth Network Rehabil Solut, CREIDO, Toronto, ON M5T 2S8, Canada
[5] Univ Toronto, Dept Publ Hlth Sci, Toronto, ON, Canada
[6] Univ Toronto, Dept Hlth Policy Management & Evaluat, Toronto, ON, Canada
[7] Toronto Western Res Inst, Div Hlth Care & Outcomes Res, Toronto, ON, Canada
[8] Inst Work & Hlth, Toronto, ON, Canada
[9] Stanford Univ, Sch Med, Dept Orthopaed Surg, Stanford, CA 94305 USA
[10] Stanford Univ Hosp & Clin, Orthopaed Spine Ctr, Stanford, CA USA
[11] Stanford Univ Hosp & Clin, Spinal Surg Serv, Stanford, CA USA
[12] NYU, Dept Orthoped & Environm Med, New York, NY USA
[13] NYU, Sch Med, Program Ergonom & Biomech, New York, NY USA
[14] NYU, Grad Sch Arts & Sci, New York, NY USA
[15] NYU, Med Ctr, OIOC, New York, NY 10016 USA
[16] Karolinska Inst, Inst Environm Med, S-10401 Stockholm, Sweden
[17] Univ British Columbia, Dept Med, Vancouver, BC V5Z 1M9, Canada
[18] Occupat Hlth & Safety Agcy Healthcare, Vancouver, BC, Canada
[19] Endocrinol Analgesia & Inflammat Merk & Co, Rahway, NJ USA
[20] Univ Calif Irvine, Dept Neurol, Irvine, CA 92717 USA
[21] Univ Calif Los Angeles, Sch Publ Hlth, Dept Epidemiol, Los Angeles, CA 90024 USA