Modified Frailty Index (mFI) predicts 30-day complications after microsurgical breast reconstruction

Frailty lacks a universal definition. The modified Frailty Index (mFI) using patient comorbidities can be used to measure frailty. We hypothesized that mFI predicts 30-day complications after microsurgical breast reconstruction. American College of Surgeons' (ACS) National Surgical Quality Improvement Project (NSQIP) was investigated to identify patients undergoing microsurgical breast reconstruction between 2005-2014 using Current Procedure Terminology (CPT) code, 19364. We used mFI as a measure of frailty. The patients were assigned a frailty score based on the number of preoperative comorbid conditions as defined by the mFI. Other risk indices used include age, BMI, wound class, ASA class. Stratification was performed in ascending order for each. The outcome measure was aggregate 30-day complications. Regression analysis was performed followed by Receptor Operating Characteristic (ROC) curve to determine the accuracy of each risk index in predicting 30-day complications. Of the 3237 patients 24% experienced complications. Univariate logistic regression analysis found odds ratio of complications for frailty score 1 = 22.1 (CI = 17.9-27.3, p < 0.01), and 2 = 28 (CI = 18.3-43, p < 0.01) compared to frailty score = 0. ROC curve demonstrated mFI with the highest concordance score (c-score = 0.816). Multivariable logistic regression found frailty as the strongest independent predictor of 30-day aggregate complications adjusted OR = 22.24, CI = 17.77-27.82, p < 0.01 when compared to other risk indices. The modified Frailty Index is a simple, reliable, and objective tool that can be used to predict postoperative complications after microsurgical breast reconstruction. The application of this tool can help microsurgeons preoperatively identify patients who are at high risk.Abbreviations: ACS: American College of Surgeons; ASA: American Society of Anesthesiologists; BMI: body mass index; CHF: congestive heart failure; CPT: current procedural terminology; COPD: chronic obstructive pulmonary disease; CVA: cerebrovascular accident; DM: diabetes mellitus; IRB: institutional review board; mfi: modified frailty index; MI: myocardial infarction; NSQIP: national surgical quality improvement program; PVD: peripheral vascular disease; ROC: receptor operating characteristic; TIA: transient ischemic attach.