1 Michael G. DeGroote Institute for Pain Research and Care (Busse), Department of Anesthesia (Busse, Ebrahim) and Department of Clinical Epidemiology and Biostatistics (Busse, Ebrahim), McMaster University, Hamilton, Ont.; Faculty of Medicine (Bruun-Meyer), University of Toronto, Toronto, Ont.; Stanford Prevention Research Center, Department of Medicine (Ebrahim), Stanford University, Stanford, Calif.; Swiss Academy of Insurance Medicine, University Hospital Basel (Kunz), Basel, Switzerland bussejw@mcmaster.ca.
2 Michael G. DeGroote Institute for Pain Research and Care (Busse), Department of Anesthesia (Busse, Ebrahim) and Department of Clinical Epidemiology and Biostatistics (Busse, Ebrahim), McMaster University, Hamilton, Ont.; Faculty of Medicine (Bruun-Meyer), University of Toronto, Toronto, Ont.; Stanford Prevention Research Center, Department of Medicine (Ebrahim), Stanford University, Stanford, Calif.; Swiss Academy of Insurance Medicine, University Hospital Basel (Kunz), Basel, Switzerland.