[1] Univ Alabama Birmingham, Birmingham, AL 35294 USA
[2] Phys Innovat LLC, Birmingham, AL 35213 USA
[3] Advisory Board Co, Washington, DC 20037 USA
[4] Univ Massachusetts, Sch Med, Dept Quantitat Hlth Sci, Worcester, MA 01655 USA
[5] United Cerebral Palsy Greater Birmingham, Birmingham, AL 35205 USA
[6] Dept Hlth Serv Adm, Birmingham, AL 35294 USA