5-Item Modified Frailty Index as a Preoperative Predictor of Morbidity Following Minimally Invasive Partial Nephrectomy

Objective: To apply the modified frailty index-5 (mFI-5) to those patients undergoing minimally invasive partial nephrectomy (MIPN) to examine the relationship between frailty and postoperative outcomes. Methods: Using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, data were retrospectively reviewed between 2012 and 2018 for cases coded for MIPN. The mFI-5 score was defined on a scale of 1 to 5, with each patient receiving one point per each of the following comorbidities: congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), diabetes mellitus, hypertension that requires medication and functional health status of partial or total dependence prior to surgery. Complications were examined within the first 30 days postoperatively. Using univariate and multivariate logistic regression, postoperative outcomes were obtained and stratified based on frailty score. Results: Of the 18,904 cases identified between 2012 and 2018, mFI-5 score was 0 for 38.0% of patients, 1 for 42.8%, ≥2 for 19.2%. With increasing mFI-5 score, a significant increase in multiple postoperative morbidities were identified (P <0.05). 11.2% of patients with mFI-5 ≥2 had complications vs 5.3% with mFI-5 of 0 and 7.8% mFI-5 of 1, P <0.05. Multivariate analysis revealed nearly 50% increase in the odds of having an overall complication for patients with mFI-5 score ≥2 (OR = 1.48, 95% CI 1.22 - 1.80, P <0.001). Conclusion: The mFI-5 is a well defined and easily ascertainable predictor of postoperative outcomes in those undergoing MIPN and could be used preoperatively to identify and counsel those at increased risk for morbidity.