Title: Self-monitoring of blood pressure in pre-hypertension to reduce cardiovascular risk: a feasibility study
Funder: Department of Health and Social Care

Abstract: Background: Prehypertension (PHT) currently affects around 40% of UK adults and is directly associated with increased risk of cardiovascular disease (CVD), as well as progression to hypertension itself. Lifestyle changes can reduce these risks, but there is little evidence of what interventions are feasible, acceptable and effective. Previous research has shown that self-monitoring of blood pressure (BP) is highly effective in managing hypertension. However, self-monitoring in PHT has not been systematically explored. Aims and Objectives: The aim of this study is to determine the feasibility and acceptability of using self-monitoring of BP in people with PHT. It will inform the design of a future trial to investigate if self-monitoring is effective in detecting, and increasing awareness of, PHT, and in encouraging lifestyle change. The primary objectives are: a) Determine the willingness of people in PHT range, and service providers, to engage with a self-monitoring intervention; b) Evaluate acceptability of the intervention and study processes. Secondary and tertiary objectives will contribute to the design and content of a future multi-centre randomised trial (RCT). Methods: Design and setting: Prospective, non-randomised feasibility study, with a mixed-methods approach, based in general practice, pharmacy and workplace provider settings, that offer the NHS-commissioned health check across Lancashire. Sample and recruitment: People with BP in the PHT range identified from electronic records in three general practices, or from NHS health checks conducted across three pharmacies and three Blue HealthCare workplace sites. Eligibility criteria: Aged 18+, BP 120-139mmHg systolic and/or 80-89mmHg diastolic, no previous hypertension diagnosis. We will recruit 112 individuals to retain an estimated 90 patients at follow-up. Intervention: Participants will be asked to self-monitor BP on three days every month for 6-months, sending their readings to the research team monthly. If readings are in the hypertensive range for two consecutive months, they will be asked to inform their GP. This study will not involve a lifestyle component, but will evaluate participants' self-initiated lifestyle modifications. Data collection and analysis: Data will be collected at baseline, 6 and 12 months. We will also conduct up to 35 (participants n=20, health care professionals n=15) semi-structured interviews, using the Theoretical Domains Framework to explore experiences of self-monitoring, benefits and barriers of self-monitoring and areas for improvement, and awareness and knowledge of PHT including any unintended negative consequences. We will also conduct a focus group with 4-8 participants to begin co-developing a lifestyle intervention. Descriptive analysis and, where feasible, subgroup analyses for the primary and secondary outcomes will be performed. We will investigate parameters including recruitment and retention rates for any future trial. We will collect survey data on the economic value and acceptability of the intervention and on its health resource implications. Timeline: The study will commence January 2021, and we will complete this feasibility study within 30 months. Impact and dissemination: Should a full trial be indicated, the key output of this study will be a protocol and grant application for a full Randomised Controlled Trial. There will also be academic papers and conference presentations.

Lay abstract: Aim: Self-monitoring of blood pressure may increase awareness of blood pressure levels and prompt people with raised blood pressure (prehypertension) to modify their lifestyle (e.g. diet, smoking, and physical activity). This research will examine whether self-monitoring is practical and acceptable for people with raised blood pressure and their GPs. Background: High blood pressure increases the risk of cardiovascular disease. Raised blood pressure occurs before someone crosses the threshold of high blood pressure. People are not usually made aware of raised blood pressure, even though it is known to increase the risk of cardiovascular disease. By identifying and alerting people to raised blood pressure, an intervention might prevent cardiovascular disease. This may protect health and quality of life. It may also help health professionals to reduce the cost and workload caused by preventable cardiovascular diseases. Design and methods: We will recruit people from pharmacies, GPs and work-place providers in Lancashire offering the NHS Health Check . People aged 18+, with raised blood pressure, will be invited to take part. Participants must not have had a diagnosis of high blood pressure, nor have been on blood pressure medications. We will provide equipment for participants to self-monitor their blood pressure at home. They will record two blood pressure readings on three days every month, for six months. In order to find out if self-monitoring is acceptable to participants and the health professionals, we will interview them. We will ask about their experiences with self-monitoring, its benefits, any problems they have experienced, and how it might be improved. To find out if self-monitoring is feasible for members of the public we will assess the time taken to recruit the target number of eligible people, the number of people who are recruited but who do not complete the study, and whether people actually check their blood pressure on schedule. This will help decide whether a future larger study is needed, looking at the impact self-monitoring has on people s health, longer-term. Patient and public involvement: To help with designing our research we held discussion groups, with members of the public (some with raised and some with high blood pressure), about the positives for self-monitoring blood pressure and the benefits gained from it. We invited one of these volunteers (Paul Heyworth) to become a member of our research team. Going forward, Paul will attend research meetings, help to design study materials and will work with participants, helping to interview them. Dissemination: We will share our findings with health professionals and researchers through journal articles, conferences and reports. We will share our work with members of the public, via articles for The Conversation website, with local and national media, with a project website and via Twitter.

Research activity codes: 7.1 INDIVIDUAL CARE NEEDS;7.3 MANAGEMENT AND DECISION MAKING
Health categories: CARDIOVASCULAR