Modified 5-Item Frailty Index: A Potential Tool for Assessing the Impact of Frailty on Postoperative Morbidity Following Nerve Pedicle Transfer Surgery

Introduction: The modified 5-item frailty index (mFI-5) is a comorbidity-based risk stratification tool that has been shown to predict adverse events following various neurological surgeries.

Methods: The 2011-2021 American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) dataset was used to identify patients undergoing Nerve Pedicle Transfer Surgery as a primary procedure. The mFI-5 score was calculated based on the presence of the 5 comorbidities: congestive heart failure within 30 days prior to surgery, insulin-dependent or noninsulin-dependent diabetes mellitus, chronic obstructive pulmonary disease, partially dependent or totally dependent functional health status at time of surgery, and hypertension requiring medication. Multivariate analysis was used to assess the independent impact of increasing mFI-5 score on postoperative 30-day morbidity while controlling for baseline clinical characteristics.

Results: A total of 177 patients (34.5% females, 45.58 ± 15.66 years) were included in this study. The mFI-5 was divided into three categories, 0, 1, and 2+. Out of the 177 patients, 63.8% had an mFI-5 of 0, 27.7% had 1, and 8.5% had 2+. On univariate analyses, there is no significant difference in most post-operative complications between the mFI-5 categories, including sepsis, septic shock, unplanned reoperation, wound dehiscence, pneumonia, urinary tract infection, and bleeding. There is a significant difference between the categories for deep vein thrombosis (p=0.004) and myocardial infarction (p=0.004) post-operatively. On multivariate logistic regression, increasing mFI-5 score versus mFI-5 = 0 was associated with higher odds of overall complications (mFI-5 = high: odds ratio [OR] 3.47 CI: 0.64 – 18.10, p=0.150).

Conclusion : This study demonstrates that frailty, when measured using the mFI-5, independently predicts some post-operative complications after NPT surgery. These findings are important for risk stratification in patients undergoing NPT surgery and for standardization in reporting outcomes after the procedure.