1. Department of Neurology University of Michigan Medical School Ann Arbor Michigan USA
2. University of Michigan Institute of Social Research Ann Arbor Michigan USA
3. Department of Physical Medicine and Rehabilitation University of Michigan Medical School Ann Arbor Michigan USA
4. Department of Health Behavior and Health Education University of Michigan School of Public Health Ann Arbor Michigan USA
5. Department of Life Sciences Texas A&M Corpus Christi Corpus Christi Texas USA
6. Department of Internal Medicine University of Michigan Medical School Ann Arbor Michigan USA
7. Veterans Affairs Ann Arbor Center for Clinical Management Research Ann Arbor Michigan USA
8. University of Michigan School of Public Health Center for Social Epidemiology and Population Health Ann Arbor Michigan USA