1. Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Tulsa, OK, USA
2. Department of Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
3. Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
4. Department of General Medicine, Federal Government Polyclinic Hospital, Islamabad, Pakistan
5. Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA