[1] Case Western Reserve Univ, PBRN Shared Resource, Dept Family Med & Community Hlth, Cleveland, OH 44106 USA
[2] Florida State Univ, Dept Behav Sci & Social Med, Coll Med, Tallahassee, FL 32306 USA
[3] Oregon Hlth & Sci Univ, Sch Med, Oregon Rural Practice Based Res Network, Portland, OR 97201 USA
[4] Wayne State Univ, Sch Med, Metropolitan Detroit Practice Based Res Network, Dept Family Med & Publ Hlth Sci,MetroNet, Detroit, MI USA