1. Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, USA.
2. Department of Physical Medicine and Rehabilitation, Case Western Reserve University, MetroHealth System, Cleveland, Ohio, USA.
3. Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine and Sciences, Rochester, Minnesota, USA.
4. Department of Physical Medicine and Rehabilitation, University of California, Irvine, Orange, California, USA.
5. Biostatistics Collaboration Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
6. H. Ben Taub Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas, USA.
7. Center for Innovations in Quality, Effectiveness and Safety, Michael E. DeBakey VA Medical Center, Houston, Texas, USA.
8. Department of Rehabilitation Medicine, UT Health Science Center San Antonio, San Antonio, Texas, USA.
9. Rehabilitation Institute, MemorialCare Long Beach Medical Center, Long Beach, California, USA.