[1] Emory Univ, Rollins Sch Publ Hlth, Dept Epidemiol, Atlanta, GA 30322 USA
[2] Univ Texas Houston, Sch Publ Hlth, Dept Epidemiol Human Genet & Environm Sci, Houston, TX USA
[3] Michigan State Univ, Dept Epidemiol & Biostat, E Lansing, MI 48824 USA
[4] Michigan Dept Community Hlth, Bur Epidemiol, Div Environm Hlth, Lansing, MI USA
[5] Emory Univ, Dept Pediat, Atlanta, GA 30322 USA
[6] Emory Univ, Rollins Sch Publ Hlth, Dept Environm Hlth, Atlanta, GA 30322 USA