1 Surgical Outcomes and Quality Improvement Center (SOQIC), Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
2 Center for Health Services and Outcomes Research, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
3 Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern Institute for Comparative Effectiveness Research in Oncology, Northwestern University, Chicago, Illinois.