1 Department of Rehabilitation Medicine, University of Washington, Seattle, WA; Comparative Effectiveness, Cost and Outcomes Research Center, University of Washington, Seattle, WA. Electronic address: friedlyj@uw.edu.
2 Department of Physical Medicine and Rehabilitation, University of Colorado, Denver, CO.
3 Department of Rehabilitation Medicine, University of Washington, Seattle, WA; University of Washington Center on Outcomes Research in Rehabilitation, Seattle, WA.
4 Seattle Quality of Life Group, University of Washington, Seattle, WA.