[1] Johns Hopkins Bloomberg Sch Publ Hlth, Ctr Human Nutr, Dept Int Hlth, Baltimore, MD 21287 USA
[2] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, 2024 E Monument St,Ste 2-500, Baltimore, MD 21287 USA
[3] Welch Ctr Prevent Epidemiol & Clin Res, Baltimore, MD USA
[4] Univ Minnesota, Sch Publ Hlth, Div Epidemiol & Community Hlth, Minneapolis, MN USA