Self-reported health change in haemodialysis recipients modulates the effect of frailty upon mortality and hospital admissions: outcomes from a large prospective UK cohort

BACKGROUND: Frailty among haemodialysis patients is associated with hospitalisation and mortality, but high frailty prevalence suggests further discrimination of risk is required. We hypothesised that incorporation of self-reported health with frailty measurement may aid risk stratification.

METHODS: Prospective cohort study of 485 prevalent haemodialysis recipients linked to English national datasets. Frailty Phenotype (FP), Frailty Index (FI), Edmonton Frail Scale (EFS), Clinical Frailty Scale (CFS) and self-reported health change were assessed. Mortality was explored using Fine and Gray regression, and admissions by negative binomial regression.

RESULTS: Over a median 678 (IQR: 531-812) days, there were 111 deaths, and 1241 hospitalisations. Increasing frailty was associated with mortality on adjusted analyses for FP (SHR 1.26, 95% C.I. 1.05-1.53, P = 0.01), FI (SHR 1.21, 95% C.I. 1.09-1.35, P = 0.001), and CFS (SHR 1.32, 95% C.I. 1.11-1.58, P = 0.002), but not EFS (HR 1.08, 95% C.I. 0.99-1.18, P = 0.1). Health change interacted with frailty tools to modify association with mortality; only those who rated their health as the same or worse experienced increased mortality hazard associated with frailty by FP (Pinteraction = 0.001 and 0.035 respectively), FI (Pinteraction = 0.002 and 0.007 respectively), and CFS (Pinteraction = 0.009 and 0.02 respectively). CFS was the only frailty tool associated with hospitalisation (incidence rate ratio 1.12, 95% CI 1.02-1.23, P = 0.02).

CONCLUSIONS: We confirm the high burden of hospitalisation and mortality associated with haemodialysis patients regardless of frailty tool utilised and introduce the discriminatory ability of self-reported health to identify the most at-risk frail individuals.