[1] Baystate Med Ctr, Ctr Qual Care Res, Springfield, MA 01199 USA
[2] Baystate Med Ctr, Div Gen Internal Med, Springfield, MA 01199 USA
[3] Baystate Med Ctr, Div Neurol, Springfield, MA 01199 USA
[4] Tufts Univ, Sch Med, Boston, MA 02111 USA
[5] Univ Massachusetts, Sch Publ Hlth & Hlth Sci, Amherst, MA 01003 USA
[6] Cleveland Clin, Inst Med, Dept Med, Cleveland, OH 44106 USA