People who monitor their own blood pressure at home are most likely to see a benefit if they combine it with individually tailored intensive support, according to a new systematic literature review and meta-analysis published this week in PLOS Medicine by an international group led by Oxford University researchers, with contributions from Professor Jonathan Mant at the Primary Care Unit
Home blood pressure monitoring is currently recommended for people with high blood pressure so health professionals can see if their prescribed treatment is working and make necessary adjustments. While previous research has shown that self-monitoring reduces clinic blood pressure by a small but significant amount, it has remained unclear how best to implement it and for which patients it might be most useful.
In this new study, researchers searched the existing medical literature for all randomized trials including self-monitoring of blood pressure in people with high blood pressure. They then used individual patient data from 25 studies, with up to 10,487 patients in total, to evaluate the effect of self-monitoring on blood pressure levels.
The research was funded by the National Institute for Health Research (NIHR) School for Primary Care Research.
Overall, self-monitoring was associated with a clinic measurement of systolic blood pressure that was reduced by 3.2 mmHg (95% CI –4.9 to –1.6) compared to usual care at 12 months. The effect, however, was strongly influenced by the intensity of professional support. This ranged from no significant effect on blood pressure with self-monitoring alone (1.0 mmHg reduction; 95% CI –3.3 to 1.2) to a significant blood pressure reduction (6.1 mmHg reduction; 95% CI –9.0 to –3.2) when self-monitoring was combined with additional support such as with education, lifestyle counseling, or medication adjustment managed by the patient themselves.
Given blood pressure is directly related to stroke risk, the blood pressure reduction achieved using this combined approach has the potential to reduce stroke risk by 20%.
Self-monitoring was most effective in people on fewer antihypertensive medications and with higher systolic blood pressure before self-monitoring (up to 170 mmHg). It was equally effective in men and women and in most common co-morbidities (diabetes, chronic kidney disease, obesity, following myocardial infarction).
Lead author Professor Richard McManus, Professor of Primary Care at the University of Oxford and an Oxfordshire-based General Practitioner, said: “Home self-monitoring has little effect on blood pressure control unless it’s combined with individually tailored support delivered by either a nurse, physician or pharmacist. This can lead to important decreases in blood pressure and improved control with potential to reduce the risk of developing associated life-threatening conditions.”
“This represents an important finding for the tens of millions of people internationally with hypertension who could potentially access their own off-the-shelf BP monitor. While more research is needed to understand how best to implement this approach cost-effectively and in the long-term, international guidelines for blood pressure control, including those developed by the UK’s National Institute for Health and Care Excellence, should incorporate these findings to ensure this intervention becomes part of routine clinical practice.”
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Contact: Lucy Lloyd for more information
Image: Dr Jon Ferdinand, Primary Care Unit