1. Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
2. School of Public Health, West Virginia University, Morgantown, West Virginia, USA
3. Department of Internal Medicine, Texas Tech University Health Sciences Center School of Medicine, Lubbock, Texas, USA
4. Parachute, Colorado, USA
5. Graduate School of Public Health, Department of Health Policy and Management, University of Pittsburgh School of Law, Pittsburgh, Pennsylvania, USA