Comparison of feasibility, inter-instrument agreement, and prognostic value of four frailty assessment instruments in geriatric colorectal cancer patients: a 3-year multicenter prospective cohort study

Background Although multiple instruments exist to assess frailty, it remains unclear whether the association between frailty and clinical outcomes in older colorectal cancer (CRC) patients varies by the assessment tool used. Accordingly, the aim of this study was to compare the feasibility and clinical utility of four common frailty scales in this patient population. Methods We conducted a 3-year prospective cohort study involving geriatric patients (≥65 years) with CRC. Preoperative frailty was assessed using four established scales: the Clinical Frailty Scale (CFS), the Frailty Phenotype (FP), the Geriatric-8 (G-8) scale, and the 32-item Frailty Index (FI). The differences in the perioperative outcomes and postoperative one-year all-cause mortality rate were compared across the four scoring systems. Results A total of 1,096 patients were included in the primary analysis. The effective response rates and median completion times for the four frailty scales were as follows: CFS (91.1%; 6 min), FP (65.7%; 10 min), G-8 (71.6%; 8 min), and 32-item FI (58.3%; 18 min). The final analysis included 615 patients who completed all assessments. Frailty prevalence was estimated at 27.0% (CFS), 23.6% (FP), 33.0% (G-8), and 36.9% (FI). The four frailty scales demonstrated good predictive efficacy for postoperative clinically relevant complications, postoperative recovery, 30-day readmission, and one-year all-cause mortality. Multivariate regression analysis confirmed that the G-8 scale (OR = 2.412, 95%CI: 1.300–4.474, P = 0.008) and 32-item FI (OR = 3.035, 95%CI: 1.359–6.779, P = 0.017) served as independent risk factors for postoperative clinically relevant complications. Only the 32-item FI emerged as an independent predictor of 1-year all-cause mortality (HR = 2.777, 95%CI: 1.247–6.218, P = 0.020). Conclusion In conclusion, all four frailty scales demonstrated robust discriminatory capacity for clinical outcomes in older CRC patients. Although the 32-item FI exhibited a stronger independent correlation with adverse outcomes following multivariate adjustment, its clinical utility must be weighed against a longer administration time. This study provides crucial evidence to guide the selection of an appropriate frailty assessment tool based on specific clinical contexts.