R J Ellis1, C Y Ko2. 1. Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL, United States; Surgical Outcomes and Quality Improvement Center (SOQIC), Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States. Electronic address: rellis@facs.org. 2. Division of Research and Optimal Patient Care, American College of Surgeons, Chicago, IL, United States; Department of Surgery, David Geffen School of Medicine at University of California, Los Angeles, CA, United States; VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States.