[1] Univ N Carolina, Dept Med, Chapel Hill, NC 27515 USA
[2] Univ N Carolina, Dept Epidemiol, Chapel Hill, NC USA
[3] Ctr Dis Control & Prevent, Natl Ctr Hlth Stat, Hyattsville, MD 20782 USA
[4] Harvard Univ, Brigham & Womens Hosp, Div Cardiovasc, Boston, MA 02115 USA
[5] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA