[1] Univ Hawaii Manoa, John A Burns Sch Med, Dept Publ Hlth Sci, Honolulu, HI 96822 USA
[2] Stanford Univ, Sch Med, Dept Orthopaed Surg, Stanford, CA 94305 USA
[3] Stanford Univ Hosp & Clin, Orthpaed Spine Ctr, Stanford, CA USA
[4] Stanford Univ Hosp & Clin, Spinal Surg Serv, Stanford, CA USA
[5] Univ Toronto, Dept Hlth Policy Management & Evaluat, Toronto, ON M5S 1A1, Canada
[6] Inst Work & Hlth, Toronto, ON, Canada
[7] Univ Hlth Network Rehabil Solut, Toronto Western Hosp, Ctr Res ExcellenceImproved Disability Outcomes CR, Toronto, ON, Canada
[8] Toronto Western Res Inst, Div Hlth Care & Outcomes Res, Toronto, ON, Canada
[9] Univ Alberta, Sch Publ Hlth, Dept Publ Hlth Sci, Edmonton, AB T6G 2M7, Canada
[10] Univ Alberta, Sch Publ Hlth, Alberta Ctr Injury Control & Res, Edmonton, AB T6G 2M7, Canada
[11] NYU, Dept Orthopaed, New York, NY 10003 USA
[12] NYU, Dept Environm Med, New York, NY 10003 USA
[13] NYU, Sch Med, Program Egron & Biomech, New York, NY 10003 USA
[14] NYU, Grad Sch Arts & Sci, New York, NY 10003 USA
[15] NYU, Med Ctr, Occupat & Ind Orthopaed Ctr OIOC, New York, NY 10016 USA
[16] Univ British Columbia, Dept Med, Vancouver, BC, Canada
[17] Occupat Hlth & Safety Agcy Healthcare, Vancouver, BC, Canada
[18] Merck & Co Inc, Endocrinol Analgesia & Inflammat, Rahway, NJ USA
[19] Karolinska Inst, Inst Environm Med, S-10401 Stockholm, Sweden
[20] Univ Toronto, Dept Publ Hlth Sci, Toronto, ON M5S 1A1, Canada
[21] Univ Calif Irvine, Dept Neurol, Irvine, CA 92717 USA
[22] Univ Calif Los Angeles, Sch Publ Hlth, Dept Epidemiol, Los Angeles, CA 90024 USA