CognitiveImpairment and Depression As Mediators of the Relationship Between HealthLiteracy and Self-care: A Proposed Model

Introduction: Self-care (SC) can delay progression, improve symptoms, and reduce negative outcomes in heart failure (HF), yet is inadequate. Health literacy (HL), (ability to understand and act on health information), may impact patient knowledge and SC. Depression and cognition may influence the ability to perform SC. The study purpose was to examine the fit of a model of these relationships for patients with varying HL levels. Hypotheses: H1. Health literacy affects knowledge directly. H2. Self-efficacy and depression affect SC directly. H3. Cognitive impairment affects HL and knowledge directly. Self-efficacy mediates the relationship between H4: knowledge and SC and H5: depression and SC. H6. Knowledge mediates the relationship between cognitive impairment and HL on SC. Methods: HF patients were recruited from a large outpatient HF clinic. Quota sampling was utilized to recruit patients with adequate (no difficulty comprehending health information) and 50 patients with marginal (some difficulty) or inadequate (difficulty) HL, based on the Short-Form Test of Functional HL in Adults. Eligible participants completed The Dutch HF Knowledge Scale (knowledge), the Montreal Cognitive Assessment (mild cognitive impairment), the Patient Health Questionnaire-9 (depression), The SC HF Index V6.2 (SC maintenance, self-efficacy/confidence), and a demographic instrument (e.g., HF stage, date diagnosed, prior HF education). Structural equation modeling was used to determine the best-fitting model. Results: With 100 participants (N = 54 adequate, N = 34 marginal, N = 12 inadequate), the model (Fig. 1) demonstrated good fit (Chi square = 2.909, 7 degrees of freedom; CFI = 1.000; NFI = 0.972; RMSEA = 0.000). Depression was not directly related to SC; nor was knowledge related to self-efficacy. Self-efficacy was strongly related to SC. Knowledge also had a significant direct effect on SC. Approximately 20% of the variance in SC was explained by self-efficacy and knowledge. The other variables in the model had indirect effects on SC. Cognitive ability and HL both had significant effects on knowledge, while depression had a direct effect on self-efficacy. Conclusion: The proposed model was a good fit; all hypotheses except for H2 were accurate. Self-efficacy impacts SC directly but depression does not. It is important for healthcare professionals to deliver HL-appropriate education to improve disease knowledge and create opportunities for patients to improve self-efficacy to increase SC performance.