ABSTRACT
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.
ABSTRACT
BACKGROUND: Depressive symptoms are substantial among stroke survivors and their caregivers in poststroke management. Optimism and social support are known to protect against depressive symptoms. However, little is known about how optimism and social support contribute to depressive symptoms among stroke survivor-caregiver dyads. The study's purpose was to examine actor and partner effects of optimism on depressive symptoms through perceived social support among stroke survivors and caregiver dyads in the chronic stage of rehabilitation. METHODS: Stroke survivors and caregivers (N = 105 dyads) completed the survey at 2 years of follow-up after the first stroke. Depressive symptoms, optimism, and perceived social support were assessed using the Center for Epidemiologic Studies-Depression, the Life Orientation Test, and the Interpersonal Support Evaluation List. The Actor-Partner Interdependence Model Extended to Mediation analysis was used to test the indirect effect of optimism on depressive symptoms through perceived social support. RESULTS: Higher optimism was significantly associated with lower depressive symptoms for caregivers (direct actor effect, -0.6844; 95% confidence interval [CI], -0.9844 to -0.3844) and stroke survivors (direct partner effect, -0.4189; 95% CI, -0.0789 to -0.0889). Perceived social support availability significantly mediated the association between optimism and depressive symptoms for stroke survivors (indirect effect, -0.1957; 95% CI, -0.3923 to -0.0670). Caregiver perceived social support availability was also a significant mediator between caregivers' optimism and stroke survivors' depressive symptoms (indirect effect, 0.1658; 95% CI, 0.0559-0.3128). CONCLUSIONS: Intervention improving dyad members' optimism and social support would be beneficial to improve depressive symptoms of the stroke survivors and caregivers in chronic stroke management.
