Predictors of hospitalization and quality of life in heart failure: a model of comorbidity, self-efficacy and self-care

Background: Comorbidity is associated with decreased confidence or self-efficacy to perform self-care in heart failure patients which, in turn, impairs self-care behaviors. Comorbidity is also associated with increased hospitalization rates and poorer quality of life. Yet the manner in which comorbidity and self-efficacy interact to influence self-care, hospitalization, and quality of life remains unclear. Objectives: The purpose of this study was to test an explanatory model. The research questions were (1) What is the contribution of comorbidity to heart failure self-care behaviors and outcomes (i.e. hospitalization, quality of life)? and (2) Is comorbidity a moderator of the relationship between self-efficacy and heart failure self-care behaviors? Design: This was an analysis of an existing dataset of 628 symptomatic, older (mean age = 73, standard deviation (SD) = 11) male (58%) Italian heart failure patients using structural equation modeling and simple slope analysis. Results: Higher levels of self-care maintenance were associated with higher quality of life and lower hospitalization rates. Higher levels of comorbidity were associated with lower levels of self-care management. Comorbidity moderated the relationship between selfefficacy and self-care maintenance, but not self-care management. Post hoc simple slopes analysis showed significantly different slope coefficients (pdiff < .05). Specifically, in patients with less comorbidity, the relationship between self-efficacy and self-care was significantly stronger than in patients with higher comorbidity. Conclusions: Self-efficacy is importantin the self-care maintenance process at each level of comorbidity. Because higher comorbidity weakens the strength of the relationship between self-efficacy and self-care maintenance, tailoring interventions aimed at improving self-efficacy to different levels of comorbidity may be key to impacting hospitalization and quality of life.