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

Abstract

Objectives: 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.

Design: 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.

Setting: The NSQIP includes 685 participating hospitals in all 50 states, the majority being large, academic medical centers.

Participants: 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.

Interventions: No interventions were applied to any patients in this retrospective cohort study.

Measurements and main results: 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 R² difference: +6.1%) and reintubation rates (adjusted R² 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 R² 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).

Conclusions: 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.