[1] Durham Vet Affairs Healthcare Syst, Dept Med, Durham, NC USA
[2] Duke Univ, Dept Med, Div Rheumatol, Durham, NC USA
[3] Duke Univ, Dept Med & Pediat, Div Rheumatol, Durham, NC USA
[4] VA Cent Western Massachusetts VA Healthcare Syst, Leeds, MA USA
[5] Univ Massachusetts, Chan Med Sch, Dept Populat & Quantitat Hlth Sci, Worcester, MA USA
[6] Duke Univ, Div Internal Med, Sch Med, Durham, NC USA
[7] Duke Univ, Sch Med, Dept Populat Hlth Sci, Durham, NC USA