1. Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
2. Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
3. Department of Epidemiology & Biostatistics, University of California, San Francisco, San Francisco, CA, USA
4. The EMMES Corporation, Rockville, MD, USA
5. Department of Emergency Medicine, University of Michigan, Ann Arbor, MI, USA
6. National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA