[1] Univ Massachusetts, Sch Med, Meyers Primary Care Inst, Fallon Fdn, Worcester, MA 01605 USA
[2] Fallon Community Hlth Plan, Worcester, MA USA
[3] Ctr Educ & Res Therapeut, HMO Res Network, Boston, MA USA
[4] Univ Washington, Dept Pediat, Seattle, WA 98195 USA
[5] Kaiser Permanente Colorado, Denver, CO USA
[6] Harvard Univ, Sch Med, Dept Ambulatory Care & Prevent, Boston, MA USA
[7] Grp Hlth Cooperat Puget Sound, Ctr Hlth Studies, Seattle, WA 98101 USA
[8] Kaiser Permanente NW, Portland, OR USA
[9] Kaiser Permanente SE, Ctr Hlth Res, Atlanta, GA USA
[10] US FDA, Off Surveillance & Epidemiol, Ctr Drug Evaluat & Res, Silver Spring, MD USA