Psychosocial and Clinical Correlates of Fatigue in Haemodialysis Patients: the Importance of Patients' Illness Cognitions and Behaviours.

Purpose: Fatigue is commonly experienced in end-stage kidney disease (ESKD) and is associated with poor outcomes. Currently, little research has examined the psychosocial correlates of fatigue severity and its impact on renal disease patients. We predicted that psychological factors (distress, cognitions and behaviours) would be associated with fatigue severity and impairment in ESKD patients even when controlling for clinical and disease factors.

Method: One hundred seventy-four haemodialysis patients completed the Chalder Fatigue Questionnaire (fatigue severity) and the Work and Social Adjustment Scale (fatigue-related impairment) in addition to measures evaluating distress, fatigue perceptions, symptom beliefs and behaviours. Demographic and clinical data were also collected.

Results: Fatigue severity was not related to haemoglobin levels, serum albumin or dialysis vintage. In hierarchical regression models, demographic and clinical factors explained 20 % of the variance in fatigue (ethnicity, body mass index, exercise, log C-reactive protein and multimorbidity). Psychological distress (beta = 0.21, p < 0.01), negative beliefs about fatigue (beta = 0.10, p = 0.01) and unhelpful behaviours (all-or-nothing behaviour [beta = 0.28, p < 0.01] and avoidance [beta = 0.16, p < 0.01]) explained an additional 36.4 % of the variance. Fatigue-related impairment was associated with psychological distress, perceptions that symptoms indicate damage, avoidance behaviour and the level of fatigue severity.

Conclusion: Patients' mood, beliefs and behaviours are associated with fatigue in dialysis patients. Psychological interventions to alter these factors may reduce fatigue severity and fatigue-related disability in ESKD patients.