Department of Statistics, The Pennsylvania State University, University Park, PA, USA.|Department of Public Health Sciences Pennsylvania State University College of Medicine, Hershey, PA, USA.|Division of Biostatistics and Bioinformatics, Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA.|Division of Biostatistics and Bioinformatics, Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA.