Perceived Control, Functional Status, Depressive Symptoms, and Anxiety: Mediating and Moderating Influences on Health-Related Quality of Life in Patients with Heart Failure

Background Health-related quality of life (HRQoL) is poor in patients with heart failure. Psychological (ie, depressive symptoms [DS], anxiety, and perceived control) and physical (ie, functional status) factors are associated with HRQoL. The dynamic relationships among these variables and their impact on HRQoL remain unclear, limiting the ability to design effective interventions. Purpose Our aim was to evaluate a moderated mediation model, in which the association between perceived control and HRQoL was hypothesized to be mediated by DS and anxiety in the presence of a moderator, functional status. Methods Patients (N = 426) with heart failure completed the Control Attitudes Scale-Revised to measure perceived control, Duke Activity Status Index for functional status, Patient Health Questionnaire-9 for DS, Brief Symptom Inventory for anxiety, and Minnesota Living with Heart Failure Questionnaire for HRQoL. We performed a moderated parallel mediation analysis. Results Higher levels of perceived control were associated with better HRQoL through lower levels of anxiety and DS in the presence of functional status (index of moderated mediation for DS, b = 0.029; 95% confidence interval, 0.016-0.045; for anxiety: b = 0.009, 95% confidence interval, 0.002-0.018). The effect of perceived control on psychological symptoms was stronger at low and moderate functional statuses; however, this effect diminished with increasing functional status. Conclusion Functional status moderated the indirect effects of perceived control on HRQoL through DS and anxiety in patients with heart failure. Efforts to improve HRQoL by targeting perceived control may be more effective when considering DS and anxiety in patients with low to moderate levels of functional status.