[1] Edith Nourse Rogers Mem Vet Hosp, CHQOER, Bedford, MA USA
[2] Boston Univ, Sch Publ Hlth, Dept Hlth Serv, Boston, MA USA
[3] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[4] Boston Univ, Dept Math, Boston, MA 02215 USA
[5] Tufts Univ New England Med Ctr, Hlth Inst, Dept Clin Care Res, Boston, MA 02111 USA
[6] Boston VA Healthcare Syst, Normat Aging Study, Boston, MA USA
[7] Boston Univ, Boston VA Med Ctr, Sch Med, Gen Internal Med Sect, Boston, MA 02118 USA
[8] Univ Wisconsin, Sch Med, Dept Med, Gen Internal Med Sect, Madison, WI USA
[9] Univ Southern Maine, Portland, ME 04103 USA
[10] Univ Alabama Birmingham, Sch Med, Birmingham, AL USA
[11] Birmingham VAMC, Birmingham, AL USA