Clinical Frailty Scale, Surprise Question and One-year Mortality in Older Patients With Advanced CKD

Background: Frailty is common in older patients with advanced chronic kidney disease (CKD) and is associated with mortality. This study investigates whether the Clinical Frailty Scale (CFS) and Surprise Question (‘Would you be surprised if this patient died in the next 12 months?’, SQ) are associated with one-year mortality and whether combining risk assessments has benefits. Methods: Patients ≥65 years with estimated glomerular filtration rate (eGFR) 20 – 10 mL/min/1.73m 2 were included from the ongoing prospective observational cohort study DIALysis or not: Outcomes in older kidney patients with GerIatriC Assessment (DIALOGICA, first inclusion May 13 th , 2020). Frailty was screened using the CFS, the SQ was answered using clinical impression (‘gestalt’). Patients were classified ‘high risk’ with CFS-score ≥5 and/or SQ-answer ‘no’. Four subgroups were formed: High risk: CFS ≥5 & SQ ‘no’, High risk: CFS ≥5 only, High risk: SQ ‘no’ only and Low risk: CFS <5 & SQ ‘yes’. Associations with one-year mortality were explored using Kaplan-Meier curves and adjusted Cox proportional hazards models. Results: Overall, 589 patients were included (male sex 70%, mean age 77±6 years, mean eGFR 15±3 mL/min/1.73m 2 ). CFS-score ≥5 was found in 125 patients (21%), 112 patients (19%) had SQ-answer ‘no’. Both CFS-score ≥5 (adjusted HR 3.09, 95% CI 1.75;5.54) and SQ-answer ‘no’ (adjusted HR 1.96, 95% CI 1.09;3.52) were associated with higher mortality risk. Subgroup High risk: CFS ≥5 & SQ ‘no’ had the highest mortality risk (adjusted HR 3.37, 95% CI 1.65;6.91). Conclusions: Both CFS-score ≥5 and SQ-answer ‘no’ are associated with higher one-year mortality risk in older patients with advanced CKD. The strongest association with mortality was found by combining both assessments, when both indicate high risk. These findings may help older patients and nephrologists make better informed treatment decisions and initiate timely advance care planning conversations.