Does the EQ-5D capture the effects of physical and mental health status on life satisfaction among older people? A path analysis approach.

Abstract

To examine the extent to which EQ-5D utility scores capture the effect of mental and physical health status on life satisfaction (LS) in older adults. Retrospective cohort study of 884 patients aged ≥70years from 15 general practices in Ireland, including medical records, pharmacy claims, and self-completion questionnaire. Path analysis was used to evaluate the direct and indirect effects of: (1) chronic disease burden (based on medications data); (2) activity limitation (basic and instrumental activities of daily living); (3) anxiety symptoms and; (4) depressive symptoms (Hospital Anxiety and Depression Scale) on LS (Life Satisfaction Index Z), via a utility score based on responses to the EQ-5D scale. Utility scores were calculated using UK time trade-off utility weights. Covariates included age and socioeconomic status. The final path model fitted the data well (goodness of fit χ2=7.5, df (7), p=0.37). The direct effects of chronic disease burden and disability on LS were not statistically significant and were excluded from the final model, indicating that EQ-5D score mediated 100% of the total effect on LS. The direct and indirect effects of anxiety and depression on LS were statistically significant, but the size of the indirect effect was small (4% of the total effect for anxiety and 6% of the total effect for depression). The EQ-5D does not adequately capture the effects of anxiety and depression on LS among older adults, suggesting that it may lead to inaccurate assessments of the effectiveness of interventions in this cohort.