[1] Univ Massachusetts, Sch Med, Fallon Fdn, Meyers Primary Care Inst, Worcester, MA 01605 USA
[2] Fallon Commun Hlth Plan, Worcester, MA USA
[3] Ctr Educ & Res Therapeut, HMO Res Network, Denver, CO USA
[4] Kaiser Permanente Colorado, Denver, CO USA
[5] Harvard Univ, Sch Med, Dept Ambulatory Care & Prevent, Boston, MA 02115 USA
[6] Harvard Pilgrim Hlth Care, Boston, MA USA
[7] Grp Hlth Cooperat Puget Sound, Ctr Hlth Studies, Seattle, WA 98101 USA
[8] Hlth Partners Res Fdn, Minneapolis, MN USA
[9] Kaiser Permanente Georgia, Atlanta, GA USA
[10] Kaiser Permanente NW, Portland, OR USA
[11] US FDA, Ctr Drug Evaluat & Res, Off Surveillance & Epidemiol, Silver Spring, MD USA