[1] Johns Hopkins Univ, Sch Med, Ciccarone Ctr Prevent Cardiovasc Dis, Baltimore, MD 21205 USA
[2] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD 21205 USA
[3] St Agnes Hosp, Dept Med, Baltimore, MD USA
[4] Univ Minnesota, Sch Publ Hlth, Div Epidemiol & Community Hlth, Minneapolis, MN USA
[5] Lab Corp Amer Holdings, Morrisville, NC USA
[6] Univ Washington, Dept Epidemiol, Seattle, WA 98195 USA