[1] Univ Massachusetts, Med Sch, Dept Family Med & Community Hlth, 55 Lake Ave N, Worcester, MA 01605 USA
[2] Univ Massachusetts, Med Sch, Meyers Primary Care Inst, 55 Lake Ave N, Worcester, MA 01605 USA
[3] Vanderbilt Univ, Med Ctr, Nashville, TN USA
[4] Univ Penn, Perelman Sch Med, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[5] Humana Comprehens Hlth Insights Inc, Louisville, KY USA
[6] Harvard Med Sch, Dept Populat Med, Boston, MA 02115 USA
[7] Harvard Pilgrim Healthcare Inst, Boston, MA USA
[8] US FDA, Off Surveillance & Epidemiol, Ctr Drug Evaluat & Res, Silver Spring, MD USA