[1] Vanderbilt Univ, Sch Med, Dept Orthopaed Surg & Rehabil, Nashville, TN 37232 USA
[2] Washington DC Vet Affairs Med Ctr, Dept Psychol, Washington, DC USA
[3] Loyola Univ Maryland, Dept Psychol, Baltimore, MD USA
[4] Johns Hopkins Med, Dept Phys Med & Rehabil, Baltimore, MD USA
[5] Vanderbilt Univ, Sch Med, Dept Biostat, Nashville, TN 37232 USA
[6] Johns Hopkins Med, Dept Orthopaed Surg, Baltimore, MD USA