University of Georgia - Department of Epidemiology and Biostatistics, University of Georgia - Department of Epidemiology and Biostatistics, Peking University - Institute of Child and Adolescent Health, University of Georgia - Department of Epidemiology and Biostatistics, University of Georgia - Department of Epidemiology and Biostatistics, University of Georgia - Department of Epidemiology and Biostatistics, University of North Carolina (UNC) at Chapel Hill and Peking University - Institute of Child and Adolescent Health