Validity and reliability of the caregiver contribution to self-care of heart failure index version 2

Background: Lay caregivers are important in contributing to self-care of patients with heart failure (HF). The Caregiver Contributions to Self-Care of Heart Failure Index (CC-SCHFI) measures these contributions, but after developing the Situation-Specific Theory of Caregiver Contributions to Heart Failure Self-Care, the CC-SCHFI needed updating to reflect the theory. Objective: The aim of this study was to test the psychometric characteristics of the CC-SCHFI 2 that measures caregiver contributions (CC) to HF self-care with 3 scales: CC to self-care maintenance, CC to symptom perception, and CC to self-care management. Methods: This is a cross-sectional study. We tested the CC-SCHFI 2 with confirmatory factor analysis, internal consistency, item-total correlations, and test-retest reliability. With the CC-SCHFI 2, we also administered the Self-Care of Heart Failure Index v.7.2 to patients and the Caregiver Contribution to Heart Failure Self-Care Scale to caregivers to assess concurrent validity. Results: A sample of 277 caregivers was enrolled (mean [SD] age, 52.7 [14.9] years; 70.4% female). In confirmatory factor analysis, each CC-SCHFI 2 scale had supportive fit indices: comparative fit index ranged between 0.94 and 0.95, and root mean square error of approximation ranged between 0.05 and 0.07. Internal consistency of the 3 scales was evident with a Cronbach α between .81 and .83 and a global reliability index between 0.79 and 0.86. Item-total correlations were all greater than 0.30. In concurrent validity testing, there were significant correlations between the CC-SCHFI 2 and the Self-Care of Heart Failure Index v.7.2 and the Caregiver Contribution to Heart Failure Self-Care Scale. Test-retest reliability showed intraclass correlation coefficients between 0.72 and 0.91. Conclusions: Testing of the CC-SCHFI 2 supported validity and reliability, indicating that the instrument can be used in clinical practice and research to evaluate CC to the self-care of patients with HF.