[1] Univ Pittsburgh, Sch Med, Div Gen Internal Med, Pittsburgh, PA USA
[2] Univ Calif San Francisco, Div Gen Internal Med, San Francisco, CA 94143 USA
[3] VA Pittsburgh Healthcare Syst, Ctr Hlth Equ Res & Promot, Pittsburgh, PA USA
[4] Univ Colorado, Sch Med, Off Dean, Denver, CO USA
[5] Univ Pittsburgh, Sch Med, Div Pulm Allergy & Crit Care Med, Pittsburgh, PA USA