Baseline frailty status, not advanced patient age, predicts epilepsy surgery outcomes: An analysis of 696 patients from the NSQIP database.

ABSTRACT

OBJECTIVE: Preoperative risk stratification of patients undergoing epilepsy surgery remains challenging. Recently, the efforts to look beyond age alone as an outcomes predictor has resulted in the development of measures of physiological reserve, or 'frailty indices.' The most frequently cited index in neurosurgery is the 11-item or 5-item modified frailty index (mFI11 or mFI-5). The present study aimed to use a large national registry to evaluate the effect of frailty (as measured by mFI-5 versus age on postoperative outcomes of patients undergoing epilepsy surgery. METHODS: The National Surgical Quality Improvement Program (NSQIP) database, overseen by the American College of Surgeons (ACS), was used to extract data for patients undergoing epilepsy surgery from 2015 to 2019. Univariate and multivariate analyses for age and mFI-5 were performed for the following 30-day outcomes of extended length of hospital stay (eLOS) and non-home discharge (NHD). The effect sizes were summarized by odds ratio and associated 95 % confidence intervals. Receiver operating characteristic (ROC) curve analysis, including area under the curve (AUC), was used to quantify the discrimination. RESULTS: Univariate and multivariate analyses demonstrated that frailty statuses from mFI-5, not age, were significantly predictive of eLOS and NHD. On ROC curve analysis, mFI-5 was a stronger predictor of eLOS (C = 0.59, 95 % CI 0.54-0.64, p < 0.001) and NHD (C = 0.69, 95 % CI 0.64-0.76, p < 0.001) than age (C = 0.53, 95 % CI 0.48-0.58, p = 0.21 and C = 0.53, 95 % CI 0.46-0.59, p = 0.44, respectively). CONCLUSION: Frailty, not age, is an independent risk factor for poor postoperative outcomes, particularly eLOS and NHD, in patients undergoing epilepsy surgery. Usage of mFI-5 for preoperative risk stratification of epilepsy surgery patients can help in prognostication.