[1] Virginia Commonwealth Univ, Sch Med, Dept Internal Med, Div Qual Hlth Care, Richmond, VA 23298 USA
[2] Virginia Commonwealth Univ, Sch Med, Massey Canc Ctr, Richmond, VA 23298 USA
[3] Virginia Commonwealth Univ, Sch Med, Dept Biostat, Richmond, VA 23298 USA
[4] Virginia Commonwealth Univ, Sch Med, Dept Psychiat, Richmond, VA 23298 USA
[5] Michigan State Univ, Dept Epidemiol, E Lansing, MI 48824 USA