[1] Ann Arbor VA Healthcare Syst, Patient Safety Enhancement Program, Ann Arbor, MI USA
[2] Univ Michigan Hlth Syst, Dept Gen Med, Ann Arbor, MI USA
[3] Baystate Med Ctr, Ctr Qual Care Res, Springfield, MA USA
[4] Univ Massachussets, Sch Publ Hlth & Hlth Sci, Amherst, MA USA
[5] Univ Washington, Harborview Med Ctr, Dept Med, Seattle, WA 98104 USA
[6] Tufts Univ, Sch Med, Boston, MA 02111 USA
[7] Univ Massachusetts Amherst, Sch Publ Hlth & Hlth Sci, Amherst, MA USA