BREAKING research from the department of nephrology and transplantation at Queen Elizabeth Hospital, Birmingham, UK, and the Institute of Inflammation and Ageing, University of Birmingham, UK, suggests the Montreal Cognitive Assessment (MoCA) is effective at identifying high-risk patients on dialysis with both high and low frailty. Frailty and cognitive impairment are both common in people treated with haemodialysis and are both linked to hospitalisation and death. However, little is known about the relationship between frailty and cognitive impairment in these patients. Therefore, this study aimed to explore and compare the relationship between the two factors: to ascertain the association between cognitive impairment with hospitalisation and mortality, and to explore the interplay between frailty and cognition with respect to mortality and hospitalisation.
This prospective cohort study included 448 patients on maintenance dialysis from the FITNESS study. The association between frailty scores and cognition with hospitalisation and mortality was explored. To assess cognition, patients completed the MoCA at baseline and provided information for the frailty phenotype, Frailty Index (FI), Edmonton Frailty Scale (EFS), and Clinical Frailty Scale (CFS). MoCA scores of less than 26 indicated cognitive impairment; scores of less than 21 indicated dexterity impairment; and scores of less than 18 indicated visual impairment. Patients were followed for a median of 685 days.
A total of 1,120 hospital administrations and 103 deaths were recorded within the cohort. Cognitive impairment was identified in 77.2% of patients and a correlation between increasing frailty and poorer cognition was identified. However, multivariate analyses revealed no correlation between cognition and hospitalisation or mortality. Interestingly, hospital administrations were highest when both the MoCA and frailty scores were high or when both were low.
Benjamin M. Anderson, Department of Nephrology and Transplantation at Queen Elizabeth Hospital, and colleagues commented: “There is an interaction between MoCA scores and frailty upon the association with hospitalisation, but MoCA is not independently associated with hospitalisation or mortality.” This suggests that “the MoCA may therefore offer added discriminative value in identifying higher-risk haemodialysis populations with both high and low degrees of frailty. These results should stimulate further exploration of the interplay between frailty and cognitive impairment, particularly with regard to adverse outcomes.”