Psychometric Testing of the Self-care of Hypertension Inventory

Background: Hypertension (HTN) is a global public health issue. Self-care is an essential component of HTN treatment, but no instruments are available with which to measure self-care of HTN. Objectives: The purpose of this study is to test the psychometric properties of the Self-care of Hypertension Inventory (SC-HI). Methods: Using the Self-care of Chronic Illness theory, we developed a 24-item measure of maintenance, monitoring, and management appropriate for persons with chronic HTN, tested it for content validity, and then tested it in a convenience sample of 193 adults. Exploratory factor analysis was used to identify measure structure. Cronbach's alpha and factor determinacy scores and were used to assess reliability. Validity was tested with the Medical Outcomes Study General Adherence Scale and the Decision Making Competency Inventory. Results: Seventy percent of the sample was female; mean age was 56.4 +/- 13 years; mean duration of HTN was 11 +/- 9 years. Removal of 1 item on alcohol consumption resulted in a unidimensional self-care maintenance factor with acceptable structure and internal consistency (alpha =.83). A multidimensional self-care management factor included "consultative" and "autonomous" factors (factor determinacy score = 0.75). A unidimensional confidence factor captured confidence in and persistence with each aspect of self-care (alpha =.83). All the self-care dimensions in the final 23-item instrument were associated with treatment adherence and several with decision making. Conclusion: These findings support the conceptual basis of self-care in patients with HTN as a process of maintenance, monitoring, and management. The SC-HI confidence scale is promising as a measure of self-efficacy in self-care.