Modified Frailty Index Helps Predict Mortality and Ambulation Differences Between Genders and Racial Differences Following Major Lower Extremity Amputation

Background Major lower extremity amputation (LEA) is associated with significant morbidity and mortality. The modified frailty index (mFI-5) has been used to predict outcomes including ambulation and mortality after LEA. It remains unknown for which patient demographics the mFI-5 is a reliable predictor. Methods This was a retrospective review of all patients who underwent a first-time major LEA at our institution from 2015 to 2022. Patients were stratified into 2 risk groups based on their mFI-5 score: non-frail (mFI<3) and frail (mFI≥3) and assessed on outcomes. Results Our sample consisted of 687 patients of whom 134 (19.6%) were considered frail and 551 (80.4%) were considered non-frail. A higher mFI-5 is associated with decreased ambulation rates (OR: 0.565, P = .004), increased hospital readmission (OR: 1.657, P = .021), and increased mortality (OR: 2.101, P = .001) following major LEA. In African American patients, frail and non-frail patients differed on readmission at 90 days ( P = .008), mortality at 1 year ( P = .001), ambulatory status ( P < .001), and prosthesis use ( P = .023). In male patients, frail and non-frail patients differed on readmission at 90 days ( P = .019), death at 1 year ( P = .001), and ambulatory status ( P = .002). In Caucasian patients and female patients, frail and non-frail patients did not differ significantly on outcomes. Discussion The mFI-5 is a valuable predictor of outcomes following major LEA, specifically in males and African American patients. Moreover, surgeons should consider using frailty status to risk stratify patients and inform treatment plans.