Development and Validation of a Risk-Stratification Score for Surgical Site Occurrence and Surgical Site Infection after Open Ventral Hernia Repair Rachel L Berger, BA, Linda T Li, MD, Stephanie C Hicks, PhD, MS, Jessica A Davila, PhD, Lillian S Kao, MD, MS, FACS, Mike K Liang, MD BACKGROUND: Current risk-assessment tools for surgical site occurrence (SSO) and surgical site infection (SSI) are based on expert opinion or are not specific to open ventral hernia repairs. We aimed to develop a risk-assessment tool for SSO and SSI and compare its performance against existing risk-assessment tools in patients with open ventral hernia repair. STUDY DESIGN: A retrospective study of patients undergoing open ventral hernia repair (n ¼ 888) was con- ducted at a single institution from 2000 through 2010. Rates of SSO and SSI were deter- mined by chart review. Stepwise regression models were built to identify predictors of SSO and SSI and internally validated using bootstrapping. Odds ratios were converted to a point system and summed to create the Ventral Hernia Risk Score (VHRS) for SSO and SSI, respectively. Area under the receiver operating characteristic curve was used to compare the accuracy of the VHRS models against the National Nosocomial Infection Surveillance Risk Index, Ventral Hernia Working Group (VHWG) grade, and VHWG score. RESULTS: The rates of SSO and SSI were 33% and 22%, respectively. Factors associated with SSO included mesh implant, concomitant hernia repair, dissection of skin flaps, and wound class 4. Predictors of SSI included concomitant repair, dissection of skin flaps, American Society of Anesthesiologists class 3, wound class 4, and body mass index 40. The accuracy of the VHRS in predicting SSO and SSI exceeded National Nosocomial Infection Surveillance and VHWG grade, but was not better than VHWG score. CONCLUSIONS: The VHRS identified patients at increased risk for SSO/SSI more accurately than the National Nosocomial Infection Surveillance scores and VHWG grade, and can be used to guide clinical decisions and patient counseling. (J Am Coll Surg 2013;217:974e982. Ó 2013 by the American College of Surgeons) Ventral hernia repairs are among the most common general surgery procedures, with more than 350,000 performed in the United States each year. 1 A myriad of wound complications can occur after open ventral hernia repair (OVHR). These events are cumulatively called surgical site occurrences (SSO) and are thought to be related to patient and surgical factors. Specifically, SSO includes surgical site infection (SSI), seroma and hematoma forma- tion, wound dehiscence, and fistula formation. 2 Surgical site occurrence after OVHR can lead to chronic mesh infec- tion and hernia recurrence, both of which can lead to reop- eration and increased risk of subsequent complications. Recognizing the grave consequences of SSO, earlier efforts have been made to identify risk factors for SSO to guide patient counseling of postoperative risks and to facil- itate outcomes reporting for OVHR; yet there are several limitations to each of the existing risk-assessment tools. For example, the Ventral Hernia Working Group (VHWG) categorizes patients into 4 grades that predict the risk of SSO. Patients classified as grade 1 have a “low risk” of complications and includes patients with no Disclosure Information: Dr Liang is currently an investigator and receives grants from Lifecell and Acell. All other authors have nothing to disclose. Dr Kao is a mentor for a resident grant from the American Society of Colon and Rectal Surgeons and does not receive any salary support from this grant. Ms Berger and Dr Li contributed equally to this work. Abstract presented at the Academic Surgical Congress and the Annual Meeting of the Surgical Infection Society, New Orleans, LA, February 2013. Received May 24, 2013; Revised July 13, 2013; Accepted August 5, 2013. From the Michael E DeBakey Veterans Affairs Medical Center (Berger, Liang), Michael E DeBakey Department of Surgery, Baylor College of Medicine (Li, Liang), Department of Statistics, Rice University (Hicks), Houston VA HSR&D Center of Excellence (Davila), and Department of Surgery, The University of Texas Medical School at Houston (Kao), Houston, TX. Correspondence address: Mike K Liang, MD, Michael E DeBakey Veterans Affairs Medical Center, 2002 Holcombe Blvd, OCL (112), Houston, TX 77030. email: mkliang18@yahoo.com 974 ª 2013 by the American College of Surgeons ISSN 1072-7515/13/$36.00 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.jamcollsurg.2013.08.003