Comparison of Frailty Measures as Predictors of Outcomes After Orthopedic Surgery

Objectives: To apply the Frailty Phenotype (FP) and Frailty Index (FI) before major elective orthopedic surgery to categorize frailty status and assess associations with postoperative outcomes. Design: Prospective cohort study. Setting: Two tertiary hospitals in Boston, Massachusetts. Participants: Individuals aged 70 and older undergoing scheduled orthopedic surgery enrolled in the Successful Aging after Elective Surgery (SAGES) Study (N = 415). Measurements: Preoperative evaluation included assessment of frailty using the FP and FI. The weighted kappa statistic was used to determine concordance between the two frailty measures and multivariable modeling to determine associations between each measure and postoperative complications, postoperative length of stay (LOS) of longer than 5 days, discharge to postacute institutional care (PAC), and 300 day readmission. Results: Frailty was highly prevalent (FP, 35%; FI, 41%). There was moderate concordance between the FP and FI (κ = 0.42, 95% confidence interval (CI) 0.36–0.49). When using the FP, being prefrail predicted greater risk of complications (relative risk (RR) = 1.6, 95% CI = 1.1–2.1) and discharge to PAC (RR = 1.8, 95% CI = 1.2–2.9) than being robust, and being frail predicted more complications (RR = 1.7, 95% CI = 1.1–2.1), LOS longer than 5 days (RR = 3.1, 95% CI = 1.1–8.8), and discharge to PAC (RR = 2.3 95% CI = 1.4–3.7). When using FI, being prefrail predicted LOS longer than 5 days (RR = 2.1, 95% CI = 1.0–4.8) and discharge to PAC (RR = 1.5, 95% CI = 1.4–2.1), as did being frail (RR = 1.9, 95% CI = 1.4–2.5; RR = 3.1, 95% CI = 1.4–6.8, respectively). The other outcomes were not significantly associated with frailty status. Conclusion: FP and FI predict postoperative outcomes after major elective orthopedic surgery and should be considered for preoperative risk stratification.