1. Department of Neurology, School of Medicine; University of Washington; Seattle WA USA
2. Department of Biostatistics, School of Public Health; University of Washington; Seattle WA USA
3. Department of Epidemiology, School of Public Health; University of Washington; Seattle WA USA
4. Center for Research on Health Care; University of Pittsburgh; Pittsburgh PA USA
5. Duke Clinical Research Institute, Department of Medicine; Duke University School of Medicine; Durham NC USA
6. Department of Health Sciences, College of Life Sciences; Brigham Young University; Provo UT USA
7. Department of Family and Preventive Medicine; University of California; San Diego CA USA
8. Department of Neurology, School of Medicine; University of Pittsburgh; Pittsburgh PA USA