[1] Univ N Carolina, Sch Publ Hlth, Dept Biostat, Collaborat Studies Coordinating Ctr, Chapel Hill, NC 27514 USA
[2] Univ Minnesota, Sch Publ Hlth, Div Epidemiol, Minneapolis, MN 55455 USA
[3] NHLBI, NIH, Bethesda, MD 20892 USA
[4] Univ N Carolina, Sch Publ Hlth, Dept Epidemiol, Chapel Hill, NC USA
[5] Johns Hopkins Univ, Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[6] Univ Alabama Birmingham, Sch Publ Hlth, Dept Biostat, Birmingham, AL 35294 USA
[7] Wake Forest Univ, Sch Med, Dept Publ Hlth, Winston Salem, NC 27109 USA