[1] Univ Alabama Birmingham, Sch Med, Birmingham, AL USA
[2] Edith Nourse Rogers Mem Vet Hosp, Ctr Hlth Qual Outcomes & Econ Res, Bedford, MA USA
[3] Boston Univ, Dept Math, Boston, VA USA
[4] Boston VA Healthcare Syst, Normat Aging Study, Boston, MA USA
[5] Boston Univ, Sch Publ Hlth, Dept Epidemiol, Boston, MA USA
[6] Boston Univ, Sch Publ Hlth, Dept Hlth Serv, Boston, MA USA
[7] CitiFinancial Int, Decis Sci, Dallas, TX USA