Ann Surg 2014 Aug;260(2):311-6
*Departments of Surgery †Radiology-University of Washington Medical Center ‡University of Washington Surgical Outcomes Research Center (SORCE) §Swedish Medical Center ¶Virginia Mason Medical Center ∥Surgical Care and Outcomes Assessment Program (SCOAP) and Clinical Effectiveness Research Translation Network (CERTAIN), Seattle, WA **Skagit Valley Hospital, Mount Vernon, WA ††Denver Health Medical Center, Denver, CO ‡‡Department of Surgery, Madigan Army Medical Center, Fort Lewis, WA.