[1] Lehigh Valley Hosp Ctr, Dept Family Practice, Allentown, PA 18104 USA
[2] Univ Nebraska, Med Ctr, Eppley Canc Ctr, Omaha, NE USA
[3] Univ Texas, Dept Management Sci & Informat Syst, Austin, TX 78712 USA
[4] Case Western Reserve Univ, Ireland Canc Ctr, Cleveland, OH 44106 USA
[5] Case Western Reserve Univ, Dept Family Med, Cleveland, OH 44106 USA
[6] Case Western Reserve Univ, Dept Epidemiol & Biostat, Cleveland, OH 44106 USA
[7] Case Western Reserve Univ, Dept Sociol, Cleveland, OH 44106 USA
[8] Univ Hosp Cleveland, Cleveland, OH 44106 USA