Trajectory of frailty and association with adverse outcomes in patients with end-stage kidney disease over the first year of dialysis

Little is known about trajectory of frailty as patients with advanced chronic kidney disease transition onto dialysis. This retrospective cohort study aims to describe change in frailty from dialysis initiation over the course of the first year of treatment. Secondly, we aim to examine the association of frailty and change in frailty over time with mortality and hospitilisation. The study included incident haemodialysis or peritoneal dialysis patients. Clinical frailty scale (CFS) was recorded at dialysis start and after 6 and 12 months of treatment. Multilevel mixed effects linear regression models were used to examine change in CFS from baseline to 6 and 12 months after start of dialysis. Kruskal-Wallis tests were used to assess the association between CFS with number of hospitilisations. Cox proportional hazard models were used to examine the association of CFS with survival time after dialysis initiation. The study included 293 patients, 65% haemodialysis, 35% peritoneal dialysis. Characteristics of the patients on each modality were similar. Mean CFS pre-dialysis was 4.0 (95% CI 3.81-4.21). Time on dialysis was associated with a mean increase in CFS of 0.18 per 6 months (95% CI 0.06 to 0.31), independent of confounding variables. Frailty prior to initiation of dialysis (defined as CFS ≥ 5) was associated with increased hospitilisations, compared to the non-frail group (p = 0.011). An increase in frailty score between pre-dialysis and 6 months was associated with increased risk of mortality (HR 1.35, 95% CI 1.01-1.80). Our findings highlight the importance of pre-dialysis frailty screening in order to identify at-risk patients and inform prognosis and patient counselling. Frailty trajectory in the first 6 months of dialysis treatment is a predictor of adverse outcomes.