Using a Web-Based Approach to Assess Test–Retest Reliability of the “Hypertension Self-Care Profile” Tool in an Asian Population: A Validation Study

Essential hypertension often requires affected patients to self-manage their condition most of the time. Besides seeking regular medical review of their life-long condition to detect vascular complications, patients have to maintain healthy lifestyles in between physician consultations via diet and physical activity, and to take their medications according to their prescriptions. Their self-management ability is influenced by their self-efficacy capacity, which can be assessed using questionnaire-based tools. The “Hypertension Self-Care Profile” (HTN-SCP) is 1 such questionnaire assessing self-efficacy in the domains of “behavior,” “motivation,” and “self-efficacy.” This study aims to determine the test–retest reliability of HTN-SCP in an English-literate Asian population using a web-based approach. Multiethnic Asian patients, aged 40 years and older, with essential hypertension were recruited from a typical public primary care clinic in Singapore. The investigators guided the patients to fill up the web-based 60-item HTN-SCP in English using a tablet or smartphone on the first visit and refilled the instrument 2 weeks later in the retest. Internal consistency and test–retest reliability were evaluated using Cronbach's Alpha and intraclass correlation coefficients (ICC), respectively. The t test was used to determine the relationship between the overall HTN-SCP scores of the patients and their self-reported self-management activities. A total of 160 patients completed the HTN-SCP during the initial test, from which 71 test–retest responses were completed. No floor or ceiling effect was found for the scores for the 3 subscales. Cronbach's Alpha coefficients were 0.857, 0.948, and 0.931 for “behavior,” “motivation,” and “self-efficacy” domains respectively, indicating high internal consistency. The item-total correlation ranges for the 3 scales were from 0.105 to 0.656 for Behavior, 0.401 to 0.808 for Motivation, 0.349 to 0.789 for Self-efficacy. The corresponding ICC scores of 0.671, 0.762, and 0.720 for these respective domains showed good test–retest reliability. The correlation of the HTN-SCP scores and patients’ reported self-management measures were significant, except for keeping their food diary. HTN-SCP showed satisfactory internal consistency and test–retest reliability in an English literate Asian population. A web-based approach is feasible if similar studies are needed to validate its translated versions of the tool for wider application in the local multilingual population.