Clinical Frailty Scale at presentation to the emergency department: interrater reliability and use of algorithm-assisted assessment

Purpose: The Clinical Frailty Scale (CFS) allows health care providers to quickly stratify older patients, to support clinical decision-making. However, few studies have evaluated the CFS interrater reliability (IRR) in Emergency Departments (EDs), and the freely available smartphone application for CFS assessment was never tested for reliability. This study aimed to evaluate the interrater reliability of the Clinical Frailty Scale (CFS) ratings between experienced and unexperienced staff (ED clinicians and a study team (ST) of medical students supported by a smartphone application to assess the CFS), and to determine the feasibility of CFS assignment in patients aged 65 or older at triage. Methods: Cross-sectional study using consecutive sampling of ED patients aged 65 or older. We compared assessments by ED clinicians (Triage Clinicians (TC) and geriatric ED trained nurses (geriED-TN)) and a study team (ST) of medical students using a smartphone application for CFS scoring. The study is registered on Clinicaltrials.gov (NCT05400707). Results: We included 1349 patients aged 65 and older. Quadratic-weighted kappa values for ordinal CFS levels showed a good IRR between TC and ST (ϰ = 0.73, 95% CI 0.69–0.76), similarly to that between TC and geriED-TN (ϰ = 0.75, 95% CI 0.66–0.82) and between the ST and geriED-TN (ϰ = 0.74, 95% CI 0.63–0.81). A CFS rating was assigned to 972 (70.2%) patients at triage. Conclusion: We found good IRR in the assessment of frailty with the CFS in different ED providers and a team using a smartphone application to support rating. A CFS assessment occurred in more than two-thirds (70.2%) of patients at triage.