The impact of fatigue and psychosocial variables on quality of life for patients with motor neuron disease

Abstract

Our objective was to evaluate the direct and indirect relationships between psychosocial variables, fatigue and quality of life for patients with motor neuron disease (MND). A cross-sectional sample of 147 MND patients was recruited from five neurological care centres in England. Variables included anxiety, coping, depression, fatigue, functional status, social withdrawal and quality of life. Direct and indirect relationships between study variables were assessed using structural equation modelling (SEM), using linear values derived from Rasch analyses of study questionnaires. Following some modification, Rasch analysis confirmed the suitability of all measures for use in this population. The final SEM model consisting of anxiety, coping, depression, fatigue, social withdrawal and quality of life showed excellent fit to the data. The model accounted for 59% of the variance in quality of life and 50% of the variance in depression. In conclusion, our data support a model that explains a large degree of the variance in quality of life for MND patients. Coping was most strongly related to quality of life, with the largest proportion of its influence mediated by anxiety and depression. Significant direct effects upon quality of life were exhibited by depression, fatigue and social withdrawal.

Inter-relationship between visual symptoms, activity limitation and psychological functioning in patients with diabetic retinopathy

“…Our findings are consistent with those reported by Bookwala and Lawson,11 who found that poorer self-reported vision in older adults was associated with lower psychological functioning indirectly through activity limitation and social isolation. In a clinical study of patients with visual field defects from optic neuropathies, activity limitation mediated the relationship between objectively measured remaining visual field and psychological functioning 32.…”

“…Items were generated from a literature review,17 20 focus groups and semistructured interviews with patients with DR,6 and semistructured interviews with diabetes or ophthalmic experts, and were revised following cognitive interviews with patients with DR 16. We did not include objective measures of DR-related VI, such as VA, in our models as our self-reported measure of visual symptoms includes aspects of visual function beyond VA, such as difficulty with contrast and colour sensitivity and peripheral vision, and subjective visual symptomology has been more closely associated with QoL outcomes 11. The characteristics of the nine QoL domains are provided in table 1.…”

“…Moreover, while visual acuity (VA) is important clinically, it only explains 30%–40% of the variance in QoL 10. Therefore, assessing subjective visual symptomology, closely associated with QoL outcomes,11 and which includes aspects of the visual function system beyond VA (ie, contrast and colour sensitivity, peripheral vision and depth perception) may be more relevant.…”

“…One potentially useful framework to explain the link between visual symptoms resulting from DR/DME and psychological functioning is the activity restriction model of depressed affect 13. This model proposes that while life stressors (eg, DR and VI) contribute directly to poorer psychological functioning, poor psychological functioning can also be impacted indirectly by individuals’ inability to carry out daily activities due to the former 11. Recently, Bookwala and Lawson found that poor self-reported vision in older adults contributed to reduced psychological functioning directly and indirectly via increased activity limitation and social isolation 11.…”

“…This model proposes that while life stressors (eg, DR and VI) contribute directly to poorer psychological functioning, poor psychological functioning can also be impacted indirectly by individuals’ inability to carry out daily activities due to the former 11. Recently, Bookwala and Lawson found that poor self-reported vision in older adults contributed to reduced psychological functioning directly and indirectly via increased activity limitation and social isolation 11. However, to our knowledge, no study has examined the direct and indirect effects of activity limitations on the relationship between visual symptoms and psychological functioning using path analysis in patients with DR/DME.…”