1. From the Departments of Clinical Epidemiology and Biostatistics (S.M.M., R.K., Z.I., L.T., G.H.G., J.W.B.), Anesthesia (D.N.B., L.T., J.W.B.), Medicine (A.P., G.H.G.), and Pediatrics (L.T.) and Michael G. DeGroote Institute for Pain Research and Care (L.W., R.C., D.N.B., A.P., S.M.K., J.W.B.), McMaster University, Hamilton, Ontario, Canada; Outcomes Research Consortium, Cleveland, OH (S.M.M.); Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (A.A.); Departments of Clinical...