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