[1] Univ Massachusetts, Sch Med, Dept Quantitat Hlth Sci, Worcester, MA 01655 USA
[2] Univ Massachusetts, Sch Med, Lamar Soutter Lib, Worcester, MA USA
[3] Univ Massachusetts, Sch Med, Dept Med, Div Infect Dis & Immunol, Worcester, MA USA
[4] Univ Massachusetts, Sch Med, Dept Med, Div Gen Internal Med, Worcester, MA USA
[5] Univ Massachusetts, Sch Med, Dept Family Med & Community Hlth, Worcester, MA USA