Validity and reliability of the self-care of hypertension inventory (SC-HI) in a Brazilian population

Background: Poor self-care in patients with hypertension is associated with worse patient outcomes. The Self-Care of Hypertension Inventory (SC-HI) measures self-care in patients with hypertension and includes three scales: self-care maintenance, which measures adherence to prescribed treatments and behaviors; self-care management, which evaluates the responses to signs and symptoms of high blood pressure; and self-care confidence, which measures self-efficacy in dealing with the entire process. Objective: To test the psychometric characteristics of the Brazilian version of the SC-HI. Methods: We enrolled a sample of 360 patients with hypertension and performed confirmatory factor analysis (CFA) and exploratory factor analysis (EFA) to test the factorial structure of the SC-HI and computed the factor score determinacy coefficient to evaluate the SC-HI internal consistency reliability. Results: The sample was predominantly female (65%), mean age of 65 years (SD = 10), white (70%). The self-care maintenance scale resulted in a unidimensional scale, with supportive fit indices (CFI = 0.901, RMSEA = 0.048); the self-care management did not reflect the original factorial structure and had unsupportive fit indices. EFA showed a different factorial solution in reference to the original study. Finally, the self-care confidence scale resulted in a unidimensional scale with supportive fit indices (CFI = 0.940, RMSEA = 0.093). The reliability of the self-care maintenance, management, and confidence scales resulted in factor score determinacy coefficients of 0.83, 0.78, and 0.97 respectively. Conclusion: This study shows that the SC-HI is a valid and reliable tool to measure self-care in patients with hypertension among the Brazilian population.