TOPLINE

Frailty rated by nurses using the Clinical Frailty Scale (CFS) was independently linked to an increased risk for all-cause mortality among patients receiving maintenance dialysis; the scale performed comparably to a routinely used comorbidity-based mortality score.

METHODOLOGY

• Researchers conducted a cohort study across six dialysis centres in France (2016-2020) to evaluate the feasibility and prognostic performance of the nurse-applied CFS and whether it added predictive value for mortality beyond a comorbidity score.
• They included 792 prevalent patients undergoing kidney replacement therapy (mean age, 69 years; 57.7% men), including those on in-centre haemodialysis, self-care haemodialysis in medical dialysis units or nocturnal haemodialysis, and peritoneal dialysis.
• Frailty was assessed once for each participant using the 9-point CFS rated by trained dialysis nurses; scores were analysed both as a continuous variable (per 1-point increase) and in three prespecified categories (well: CFS score, 1-3; vulnerable: CFS score, 4-5; and frail: CFS score, 6-9) and were compared with a routinely used comorbidity-based REIN Predictive Score, calculated at the time of the CFS assessment.
• The primary outcome was all-cause mortality over 24 months following the CFS assessment, with kidney transplant treated as a competing event; patients were administratively censored at 36 months or at the end of the study period, whichever came first.
• Interrater reliability was assessed in a predefined subset of 509 patients by two independent dialysis nurses from the same unit; each nurse performed a separate CFS rating, and the second nurse was blinded to the first nurse's assessment.

TAKEAWAY

• Interrater agreement for the 9-point CFS was fair (kappa coefficient, 0.35) but improved to moderate to substantial (kappa coefficient, 0.60) when scores were grouped into three CFS categories.
• The cumulative incidence of death increased stepwise across CFS categories, from 3.56% in the well group to 10.49% in the vulnerable group and 27.27% in the frail group at 12 months and from 9.78% to 21.30% and 45.87%, respectively, at 24 months.
• Both the CFS score (subdistribution hazard ratio [sHR] per point, 1.33; P < .0001) and the comorbidity-based mortality score (sHR per point, 1.05; P = .0033) were independently associated with an increased risk for mortality.
• Discrimination was comparable between the two tools, with C-statistics at 24 months of 0.71 for the CFS score and 0.67 for the comorbidity-based score. An exploratory cutoff of 6 or higher on the CFS identified a higher-risk group for 12-month mortality.

IN PRACTICE

"The CFS showed prognostic performance comparable to the REIN Predictive Score and provided independent information beyond comorbidity, supporting its use as a complementary functional risk marker in routine dialysis care," the authors wrote.

SOURCE

This study was led by Maxime Ingwiller, MD, Hôpitaux Universitaires de Strasbourg, Strasbourg, France. It was published online on August 25, 2026, in Kidney Medicine.

LIMITATIONS

The cohort was prevalent rather than incident, introducing survivorship bias. The study was conducted in a single French region, and ethnicity was not systematically recorded. The exact timing of CFS rating relative to dialysis treatment was not standardised across centres.

DISCLOSURES

This study did not receive any funding. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.