[1] VA Boston Healthcare Syst, Res & Dev, Boston, MA USA
[2] Harvard Med Sch, Dept Psychiat, Boston, MA USA
[3] VA Bedford Healthcare Syst, Ctr Healthcare Org & Implementat Res, Bedford, MA USA
[4] Boston Univ, Pulm Ctr, Sch Med, Boston, MA USA
[5] Univ Michigan, Dept Family Med, Med Sch, Ann Arbor, MI USA
[6] Massachusetts Vet Epidemiol Res & Informat Ctr, VA Boston Healthcare Syst, Boston, MA USA
[7] Boston Univ, Sch Publ Hlth, Boston, MA USA
[8] VA Boston Healthcare Syst, Pulm & Crit Care Med Sect, Boston, MA USA
[9] Harvard Med Sch, Dept Med, Boston, MA USA
[10] VA Boston Healthcare Syst, 1400 VFW Pkwy, Boston, MA 02132 USA