Validation of the American Association for the Surgery of Trauma’s emergency general surgery breast infection grading system Brittany L. Murphy, MD, MS, a,b Matthew C. Hernandez, MD, a Nimesh D. Naik, MD, a Amy E. Glasgow, MHA, b Victor Y. Kong, MBChB, PhD, c Damian L. Clarke, MBChB, PhD, c Humza Y. Saleem, MD, a Jennifer M. Racz, MD, a Elizabeth B. Habermann, PhD, MPH, a,b and Martin D. Zielinski, MD a, * a Department of Surgery, Mayo Clinic, Rochester, Minnesota b The Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic, Rochester, Minnesota c Peitermartizburg Metropolitan Complex, Kwa-Zulu Natal, South Africa article info Article history: Received 30 January 2018 Received in revised form 1 March 2018 Accepted 15 March 2018 Available online xxx Keywords: Breast infection AAST Emergency grading system abstract Background: The American Association for the Surgery of Trauma (AAST) developed emer- gency general surgery (EGS) grading systems for multiple diseases to standardize classifica- tion of disease severity. The grading system for breast infections has not been validated. We aimed to validate the AAST breast infection grading system. Methods: Multi-institutional retrospective review of all adult patients with a breast infection diagnosis at Mayo Clinic Rochester 1/2015-10/2015 and Pietermaritzburg South African Hospital 1/2010-4/2016 was performed. AAST EGS grades were assigned by two indepen- dent reviewers. Inter-rater reliability was measured using the agreement statistic (kappa). Final AAST grade was correlated with patient and treatment factors using Pearson’s cor- relation coefficient. Results: Two hundred twenty-five patients were identified: grade I (n ¼ 152, 67.6%), II (n ¼ 44, 19.6%), III (n ¼ 25, 11.1%), IV (n ¼ 0, 0.0%), and V (n ¼ 4, 1.8%). At Mayo Clinic Rochester, AAST grades ranged from I-III. The kappa was 1.0, demonstrating 100% agreement between reviewers. Within the South African patients, grades included II, III, and V, with a kappa of 0.34, due to issues of the grading system application to this patient population. Treatment received correlated with AAST grade; less severe breast infections (grade I-II) received more oral antibiotics (correlation [0.23, P ¼ 0.0004]), however, higher AAST grades (III) received more intravenous antibiotics (correlation 0.29, P <0.0001). Conclusions: The AAST EGS breast infection grading system demonstrates reliability and ease for disease classification, and correlates with required treatment, in patients * Corresponding author. Department of Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota, 55905. Tel.: þ1 507 255 2923; fax: þ1 507 255 9872. E-mail addresses: murphy.brittany@mayo.edu (B.L. Murphy), hernandez.matthew@mayo.edu (M.C. Hernandez), naik.nimesh@mayo. edu (N.D. Naik), glasgow.amy@mayo.edu (A.E. Glasgow), victorywkong@yahoo.com (V.Y. Kong), damianclar@gmail.com (D.L. Clarke), saleem.humza@mayo.edu (H.Y. Saleem), racz.jennifer@mayo.edu (J.M. Racz), habermann.elizabeth@mayo.edu (E.B. Habermann), zie- linski.martin@mayo.edu (M.D. Zielinski). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research  august 2018 (228) 263 e270 0022-4804/$ e see front matter ª 2018 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jss.2018.03.045