1 Department of Biostatistics and Epidemiology, College of Public Health, The University of Oklahoma health Sciences Center, CHB 350, 801 NE 13(th) Street, Oklahoma City, OK. Electronic address: Michael-anderson@ouhsc.edu.
2 Department of Pediatrics, College of Medicine, The University of Oklahoma health Sciences Center, 940 NE 13(th) St., Suite 4900, Oklahoma City, Ok 73104. Electronic address: David-Bard@ouhsc.edu.