Multidimensional Determinants of Functional Status in Patients with Heart Failure.

Introduction: Functional status is a predictor of rehospitalization and mortality in patients with heart failure (HF). The purpose of this study was to test the variables in the Multidimensional Model of Functional Status (MMFS) as determinants of functional status.

Methods: Using structural equation modelling, we analysed data from 520 patients with HF to determine the best multivariate model of functional status. In the MMFS, the potential determinants of functional status include demographic, clinical, psychosocial, behavioural and symptom burden variables. We measured functional status using the Duke Activity Status Index. Other variables were collected by standardized questionnaires and patient interviews.

Results: Patients who were older, less educated, or had greater comorbidity burden or greater symptom burden had worse functional status. Sex, body mass index, depression, anxiety and social support were indirectly associated with functional status mediated by symptom burden. Being married was indirectly associated with better functional status via the pathways of more social support and fewer depressive symptoms through lower symptom burden.

Conclusion: Multidimensional variables proposed in the MMFS were directly and indirectly associated with functional status. Among these variables, symptom burden is the most important mediator. Targeting these variables, especially symptom burden, may improve patients' functional status.