1. Department of Physical Therapy, University of Delaware, Newark, Delaware, USA
2. Clinical and Translational Sciences Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania USA
3. Department of Epidemiology, University of Delaware, Newark, Delaware, USA
4. Duke Clinical Research Institute, Duke University, Durham, North Carolina, USA
5. Geriatric Research Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA
6. Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
7. Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
8. Department of Medicine, Division of Geriatric Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
9. Department of Orthopedic Surgery, Duke School of Medicine, Durham, North Carolina, USA
10. Department of Physical Therapy, University of Pittsburgh, Pittsburgh, Pennsylvania, USA