1. J.L. Maxwell, PT, DPT, OCS, Department of Physical Therapy and Athletic Training, College of Health and Rehabilitation Sciences: Sargent College, 635 Commonwealth Ave, Room 623, Boston University, Boston, MA 02215 (USA).
2. J.J. Keysor, PT, PhD, College of Health and Rehabilitation Sciences, Clinical Epidemiology Research and Training Unit, Boston University School of Medicine.
3. J. Niu, DSc, Clinical Epidemiology Research and Training Unit, Boston University School of Medicine.
4. J.A. Singh, MBBS, MPH, Birmingham Veterans Affairs Medical Center and Division of Rheumatology, Department of Medicine, University of Alabama–Birmingham, Birmingham, Alabama.
5. B.L. Wise, MD, Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California–Davis, Davis, California.
6. L. Frey-Law, PT, PhD, Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.
7. M.C. Nevitt, PhD, MPH, Department of Epidemiology and Biostatistics, University of California–San Francisco, San Francisco, California.
8. D.T. Felson, MD, MPH, Clinical Epidemiology Research and Training Unit, Boston University School of Medicine.