1. From the Stroke Prevention and Atherosclerosis Research Centre, Robarts Research Institute (D.G.H., J.D.S.), Western University, London, Ontario, Canada.
2. Division of Clinical Pharmacology, Department of Medicine (D.G.H., J.D.S.), Western University, London, Ontario, Canada.
3. Department of Clinical Neurological Sciences (D.G.H., J.D.S.), Western University, London, Ontario, Canada.
4. Department of Epidemiology and Biostatistics (D.G.H.), Western University, London, Ontario, Canada.