[1] VA Durham Healthcare Syst, Geriatr Res Educ & Clin Ctr, 508 Fulton St, Durham, NC 27705 USA
[2] Duke Univ, Dept Med, 3600 Duke Med Circle, Durham, NC 27710 USA
[3] VA Durham Healthcare Syst, Ctr Hlth Serv Res & Dev Primary Care, 411 W Chapel Hill St, Durham, VA 27701 USA
[4] VA Durham Healthcare Syst, Mental Illness Res Educ & Clin Ctr, 508 Fulton St, Durham, NC 27705 USA
[5] Duke Univ, Dept Psychiat & Behav Sci, 40 Duke Med Circle, Durham, NC 27710 USA
[6] Duke Univ, Dept Biostat & Bioinformat, 3600 Duke Med Circle, Durham, NC 27710 USA