1. Epidemiology and Biostatistics Concentration, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
2. Department of Surgery, Taibah University School of Medicine, Madinah, Saudi Arabia.
3. Department of Surgery, Johns Hopkins Surgery Center for Outcomes Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.
4. Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
5. Department of Surgery, Thoracic Surgery Service, Memorial Sloan Kettering Cancer Center, New York, New York.
6. Department of Surgery, University of Wisconsin, Madison, Wisconsin.