1
Department of Surgery, Oregon Health and Science University, Portland, Oregon, USA
2
Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
3
Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
4
Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
5
Department of Surgery, Rutgers-Robert Wood Johnson, Rutgers, New Jersey, USA
6
Department of Surgery, Carolinas Medical Center, Charlotte, North Carolina, USA
7
Department of Surgery, University of California Davis, Davis, California, USA
✉Correspondence to Dr Karen Brasel, Department of Surgery, Oregon Health and Science University, Portland, OR 97239, USA; kbrasel83@gmail.com
DZ and PC are joint first authors.
© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.