Development and evaluation of the psychometric properties of a hypertension self-care questionnaire

BACKGROUND: There are a number of tools to assess self-care in hypertension (HTN), but they do not cover all the dimensions of self-care and do not have a good reliability and validity. This study was conducted to develop and evaluate the psychometric properties of a tool for self-care assessment in HTN.METHODS: This cross-sectional, methodological study was conducted in Isfahan, Iran. An expert panel was held to assess the qualitative face validity of the tool. The content validity ratio (CVR) and content validity index (CVI) were measured. The questionnaire was distributed among ۲۰ patients to measure its internal reliability. After ۱۴ days, it was re-distributed among the same patients, as a measure of external reliability. The questionnaire was completed by ۲۰۳ patients with HTN and an exploratory factor analysis was performed in order to assess the construct validity of the tool.RESULTS: The items of the self-care tool were confirmed with a CVR ≥ ۰.۵, Kappa ≥ ۰.۷۱, I-CVI = ۰.۶۹, and intraclass correlation coefficient (ICC) = ۰.۹۵۲. The factor analysis showed that the ۱۶-item questionnaire has ۵ dimensions, including follow-up [۳ items; factor loadings (FL) = ۰.۶۱۹ to ۰.۸۶۹, and Cronbach's alpha (α) = ۰.۷۳۷], healthy lifestyle (۵ items; FL = ۰.۷۰۹ to ۰.۸۴۶, α = ۰.۷۰۳), promoting qualifications (۴ items; FL = ۰.۶۱۰ to ۰.۷۹۱, α = ۰.۵۹۴), medication therapy (۲ items; FL = ۰.۶۹۹ and ۰.۷۴۰, α = ۰.۷۱۷), and following recommendations (۲ items, FL = ۰.۵۷۷ and ۰.۷۴۴, α = ۰.۷۰۱). These ۵ dimensions explained ۶۲.۶۸۶% of the variance. The Cronbach's alpha coefficient of the final self-care assessment questionnaire was ۰.۸۳۳.CONCLUSION: The developed questionnaire proved to have appropriate psychometric properties for measuring self-care in patients with HTN.

Keywords:

Blood Pressure , Chronic Disease , Hypertension , Self-Care