Use of a Six-Item Modified Frailty Index to Predict 30-day Adverse Events, Readmission, and Mortality in Older Patients Undergoing Surgical Fixation of Lower Extremity, Pelvic, and Acetabular Fractures

INTRODUCTION: This is a retrospective study evaluating the use of a new six-item modified frailty index (MF-6) to predict short-term outcomes of patients receiving surgery for lower extremity fractures. METHODS: Patients older than 65 years undergoing open reduction and internal fixation for lower extremity, pelvic, and acetabulum fractures were identified from the American College of Surgeons National Surgical Quality Improvement Program. The MF-6 was calculated by assigning one point for each of six common conditions. Multivariable analysis was used to compare patients with an MF-6 of <3 and ≥3. Outcome measures included complications, mortality, readmission, revision surgery, and length of stay. An area under the curve receiver operator analysis was conducted to compare the MF-6 with MF-5, an existing five-item frailty index. RESULTS: Nine thousand four hundred sixty-three patients were included. Patients with an MF-6 of ≥3 were at markedly higher risk of discharge destination other than home (Exp[B] = 2.09), mortality (Exp[B] = 2.48), major adverse events (Exp[B] = 2.16), and readmission (Exp[B] = 1.82). Receiver-operating curve analysis demonstrated an area under the curve of 0.65 for mortality, 0.62 for major adverse events, and 0.62 for discharge destination other than home, all of which outperformed the MF-5. DISCUSSION: The MF-6 was correlated with a 30-day postoperative incidence of infectious complications, readmission, and discharge destination. MF-6 scores can be used to risk-stratify patient populations as shifts to value-based care continue to develop.