Exploring the Cognitive Profiles of Haemodialysis Patients using Objective and Subjective Indicators: A Cross-sectional Observational Study.

Background: Cognitive impairment is common in haemodialysis patients and associated with adverse health outcomes. Previous work focused primarily on neuropsychological tests, the gold standard measure of cognition. However, these tests reflect performance under optimal conditions rather than performance in everyday life. This study aims to assess both objective and subjective cognition in haemodialysis patients.

Methods: Adult haemodialysis patients completed measures of objective cognitive impairment (Montreal Cognitive Assessment), subjective cognitive complaints, mood and fatigue symptoms, and provided sociodemographic information. Clinical data such as comorbidity were extracted from patients' medical record.

Results: A total of 268 haemodialysis patients (mean age = 59.87 years; 42.5% female) participated. Only 25.0% of the sample had normal cognition, while the rest had either objective cognitive impairments or clinically significant cognitive complaints, or both (both objective impairments and subjective complaints: 26.1%; objective impairments without complaint: 38.4%; significant complaints without objective impairments: 10.4%). Lower education was associated with the presence of objective cognitive impairments, whereas depression was associated with the presence of clinically significant cognitive complaints. Patients who exhibited both objective cognitive impairments and significant cognitive complaints were more likely to have diabetes and higher dialysis dose (Kt/V). Patients with objective cognitive impairments but no significant complaints were significantly older.

Conclusions: The cognitive burden of haemodialysis patients can be manifested as objective impairments and/or subjective complaints. When combined the two indicators may better represent the overall cognitive well-being in this population. There is a need to screen for cognitive difficulties and develop cognitive rehabilitative strategies in dialysis settings.