Using self-blood pressure monitoring to improve hypertension control in patients with lower health literacy

Abstract

International guidelines for hypertension (HT) have recommended Self-Blood Pressure Monitoring (SBPM) to diagnose and monitoring blood pressure (BP). This study aimed at investigating patients' outcomes after a structural SBPM education program designed for patients with lower health literacy. A systematic literature review on the correlations between educational level or health literacy and SBPM was performed. Twenty-nine cross-sectional or cohort studies and nineteen interventional studies were included. Previous studies assessed the quality of SBPM by the accuracy of BP monitors, knowledge and technique of SBPM. Structural educational intervention could enhance patients' SBPM quality. Patients' educational level and health literacy were not limiting factors. A prospective open cluster randomised controlled trial was performed in five public primary care clusters (clinics). Three intervention clusters, RAMP-group (Risk Assessment and Management Program-group) (n= 152), attended multidisciplinary group education on hypertension, lifestyle modification and hands-on SBPM training. Two control clusters (n=139) attended RAMP-individual (Risk Assessment and Management Program-individual). After 18 months of treatment, there was a higher BP control rate in the intervention clusters (78.9%) Vs control clusters(36.5%). The systolic BP was reduced by 19.7mmHg and diastolic BP by 8.1mmHg in RAMP-group, while the control clusters demonstrated a 9.3mmHg reduction in systolic BP with no difference in diastolic BP. The RAMP-group participants' body weight also showed a favourable change. The practice and knowledge of SBPM were surveyed by a 10-item SBPM knowledge checklist and reviewed patients’ records 6 months later. 61.7% of the participants performed SBPM regularly. Age more than 65 (adjusted odds ratio (aOR) 2.58), not working (aOR 2.34) and adequate health literacy (aOR 2.25) predicted regular SBPM. Participants in the RAMP-group participants were 8-times more likely to have a full SBPM knowledge score than the control cluster participants (aOR 8.46). Finally, 30 selected patients with uncontrolled hypertension were recruited for an individual face-to-face interview. The qualitative research adopted the Self-regulatory Mechanism of Social Cognitive Theory as a content analysis framework. Most participants had positive experience and attitude towards SBPM, especially if clinicians or family supported them. They fear hypertensive complications, which may result in death. Permanent disability is their top concern. Normal SBPM readings were reassuring. Before attended the educational intervention, many of them learnt SBPM in a non-medical setting. Error in technique and BP readings interpretation were common. In conclusion, the structural education program targeted at patients with low health literacy could improve patients' BP outcome, knowledge and practice of SBPM. The method has high patient acceptance. The program could be promoted by understanding patients' views on hypertension.