Utility of Frailty Index in Predicting Adverse Outcomes in Patients With the Same American Society of Anesthesiologists Class in Video-assisted Thoracoscopic Surgery

To investigate the utility of the five-item Modified Frailty Index (MFI-5) as a preoperative risk-stratification tool in video-assisted thoracoscopic surgery (VATS) for patients with the same American Society of Anesthesiologists (ASA) class. This was a retrospective cohort study utilizing data from The American College of Surgeons’ National Surgical Quality Improvement Program (NSQIP) database from 2008 to 2021. The NSQIP includes 685 participating hospitals in all 50 states, the majority being large, academic medical centers. All patients undergoing VATS were identified via CPT codes in the deidentified NSQIP dataset. Patients with invalid values for any variables of interest or significant covariates were excluded. No interventions were applied to any patients in this retrospective cohort study. 69,145 patients undergoing VATS were included, with the largest number having single lobectomy (32%) or unilateral wedge resection (26%). A total of 1,277 (1.8%) had unplanned reintubation, and 1,155 (1.7%) had ventilator dependence (VentDep) >48 hours after surgery. Of these patients, 66% were ASA class 3. Overall, ASA classification had a stronger correlation with both VentDep rates (adjusted R 2 difference: +6.1%) and reintubation rates (adjusted R 2 difference: +1.5%) than the MFI-5 score. However, combining ASA class with MFI-5 score was a stronger predictor for both primary outcomes than the ASA class alone (adjusted R 2 difference: +1.5%, p < 0.001). The MFI-5 had the strongest correlation with both outcomes among ASA class 3 patients, demonstrating exponentially increasing odds of VentDep and reintubation (MFI 3 v MFI 0: odds ratio = 5.1 [3.7, 7], p = 0.002). MFI-5 also helped classify risk within ASA class 2 patients but not as reliably as for ASA class 3 (ASA class 2 reintubation: increased probability from MFI 0-1 and 1-2; VentDep: increased probability from MFI 0-1 only, p = 0.005). The MFI-5 is a comorbidity-based scale that can be calculated preoperatively and considers distinct, but complementary information to the ASA class. Among VATS patients with identical ASA classes 2 and 3, the MFI-5 further stratified risk for reintubation and ventilator dependence >48 hours postsurgery.