Association between modified frailty index and surgical outcomes in intradural skull base surgery

The objective of this study is to evaluate the impact of preoperative frailty on short-term outcomes following intradural resection of skull base lesions. The 2005-2017 ACS-NSQIP database was queried for 30-day post-operative outcomes of patients undergoing intradural resection of the skull base, extracted by CPT codes 61601, 61606, 61608, and 61616. Five-item modified frailty index (mFI) was calculated based on the history of diabetes mellitus, chronic obstructive pulmonary disease, congestive heart failure, chronic hypertension, and functional status. A total of 701 patients (58.8% female, 72.0% white) were included with a mean age of 51.8 ± 14.7 years. Compared to patients with mFI = 0 (n = 403), patients with mFI ≥ 1 (n = 298) were more likely to have higher rates of reoperation (13.4% vs. 8.7%, p = 0.045), medical complications (20.5% vs. 9.2%, p < 0.001), surgical complications (13.8% vs. 8.4%, p = 0.024), discharge to non-home facility (DNHF) (24.8% vs. 13.3%, p < 0.001), and prolonged length of hospitalization (7.3 ± 6.8 days vs. 5.6 ± 5.0, p = 0.003). Moreover, mFI = 1-3 was also associated with higher BMI, non-white race, high ASA, and older age (all p < 0.05). Upon adjusting for age, BMI, race, ASA score, and surgical site, multivariate regression analysis demonstrated that higher mFI (treated as a continuous variable) was associated with higher odds of medical complications (OR = 1.630, CI = 1.153-2.308, p = 0.006), surgical complications (OR = 1.594, CI = 1.042-2.438, p < 0.031), and LOS ≥ 10 days (OR = 1.609, CI = 1.176-2.208, p = 0.003). In conclusion, the 5-item mFI can be an independent predictor of several important short-term surgical outcomes following intradural resection of skull base lesions, warranting further investigations into its clinical utility.