ORIGINAL SCIENTIFIC ARTICLE Acute Care Surgery Model and Outcomes in Emergency General Surgery Kathleen B To, MD, FACS, Neil S Kamdar, MA, Preethi Patil, MPH, Stacey D Collins, MA, Elizabeth Seese, MS, CCRC, Greta L Krapohl, PhD, RN, Darrell (Skip) Campbell Jr, MD, FACS, Michael J Englesbe, MD, FACS, Mark R Hemmila, MD, FACS, Lena M Napolitano, MD, FACS, for the Michigan Surgical Quality Collaborative (MSQC) Emergency General Surgery Study Group and the MSQC Research Advisory Group BACKGROUND: Annually, more than 2 million patients are admitted with emergency general surgery (EGS) conditions. Emergency general surgery cases comprise 11% of all general surgery operations, yet account for 47% of mortalities and 28% of complications. Using the statewide general surgery Michigan Surgical Quality Collaborative (MSQC) data, we previously confirmed that wide variations in EGS outcomes were unrelated to case volume/complexity. We assessed whether patient care model (PCM) affected EGS outcomes. STUDY DESIGN: There were 34 hospitals that provided data for PCM, resources, surgeon practice patterns, and comprehensive MSQC patient data from January 1, 2008 to December 31, 2016 (gen- eral surgery cases ¼ 126,494; EGS cases ¼ 39,023). Risk and reliability adjusted outcomes were determined using hierarchical multivariable logistic regression analysis with multiple clinical covariates and PCM. RESULTS: The general surgery service (GSS) model was more common (73%) than acute care surgery (ACS, 27%). Emergency general surgery 30-day mortality was 4.1% (intestinal resections 11.6%). The ACS model was associated with a reduction of 31% in mortality (odds ratio [OR] 0.69; 95% CI 0.52e0.92] for EGS cases, related to decreased mortality in the intestinal resection cohort (8.5% ACS vs 12% GSS, p < 0.0001). Morbidity in EGS was 17.4% (9.7% elective); highest (40%) in intestinal resection, and PCM did not affect morbidity. We identified specific variables for an optimal EGS risk adjustment model. CONCLUSIONS: This is the first multi-institutional study to identify that an ACS model is associated with a significant 31% mortality reduction in EGS using prospectively collected, clinically obtained, research-quality collaborative data. We identified that new risk adjustment models are necessary for EGS outcomes evaluations. (J Am Coll Surg 2018;-:1e8. Ó 2018 by the American College of Surgeons. Published by Elsevier Inc. All rights reserved.) General surgery is essential to health care delivery. 1 Emer- gency general surgery (EGS) is an important component of general surgery. Annually, more than 2 million patients are admitted with EGS conditions. Timely surgical assessment and operative management of EGS patients are required nationwide. Patients who require EGS procedures repre- sent a distinct, high-risk population with frequent poor outcomes. Emergency general surgery cases comprise CME questions for this article available at http://jacscme.facs.org Disclosure Information: Authors have nothing to disclose. Timothy J Eberlein, Editor-in-Chief, has nothing to disclose. Members of the Michigan Surgical Quality Collaborative (MSQC) Emer- gency General Surgery Study Group and the MSQC Research Advisory Group who collaborated on this article are listed in the Appendix avail- able online. Support for this study: This study was funded by the American College of Surgeons Thomas R Russell, MD, FACS Faculty Research Award. Presented at the American College of Surgeons 104th Annual Clinical Congress, Scientific Forum, Boston, MA, October 2018. Received July 1, 2018; Accepted July 17, 2018. From the Departments of Surgery (To, Kamdar, Patil, Englesbe, Hemmila, Napolitano), Obstetrics and Gynecology (Kamdar), and Emergency Medi- cine (Kamdar); and the Institute for Healthcare Policy and Innovation (Kamdar), University of Michigan; and the Michigan Surgical Quality Collaborative (Collins, Seese, Krapohl, Campbell, Englesbe), Ann Arbor, MI. Correspondence address: Kathleen B To, MD, FACS, 22 S Greene St, Bal- timore, MD 21201. email: Kathleen.To@umm.edu; KathleenToMD@ yahoo.com 1 ª 2018 by the American College of Surgeons. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jamcollsurg.2018.07.664 ISSN 1072-7515/18