The effects of kidney-disease-related loss on long-term dialysis patients' depression and quality of life: Positive affect as a mediator

Background and objectives: In kidney disease, the concept of loss is widely discussed but minimally researched. It appears that dialysis patients who grieve a range of losses suffer increased depression and reduced quality of life (QoL). Limited research is partly due to the lack of a relevant loss measure. The study presented here developed a measure and tested the criterion validity of loss in relation to depression and QoL. Design, setting, participants, & measurements: In a cross-sectional observational study, 151 long-term dialysis patients were interviewed using standardized psychometric measures and the Kidney Disease Loss Scale (KDLS), developed for the study. Factor, path and multigroup analyses were conducted. Results: The factor structure and reliability of KDLS were supported. The path analyses supported the criterion validity of loss. It was a stronger contributor to depression than other clinical variables. Its effect on QoL was fully mediated by depression and positive affect (coping). The magnitude of the paths from loss to QoL through depression and positive affect was larger in home-based dialysis patients than in hospital-based patients. Conclusions: KDLS is a promising measure of loss. Patient-defined losses may contribute to the high level of depression and in turn a reduction in patients' coping and QoL. These findings suggest several points of intervention to improve long-term dialysis patients' QoL.