NIHR Signal Blood pressure self-monitoring works best when people are well-supported

Published on 21 November 2017

People with high blood pressure are more likely to have their blood pressure controlled after 12 months if they self-monitor and receive counselling by telephone compared with usual monitoring in the clinic. When people were asked to self-monitor their blood pressure with no additional support, it was no better than getting their blood pressure measured in a clinic.

This NIHR-funded review of 25 trials found that self-monitoring with counselling by telephone reduced systolic blood pressure by about 6mmHg. Self-monitoring became less effective as the amount of healthcare support and education decreased.

It is not clear what the optimum frequency of checks is, but involving people in monitoring their condition is in line with NICE guidelines. The review did not look at the costs involved in providing the additional support. The accuracy and maintenance of home blood pressure machines also need to be taken into account, but the results look promising.

Blood pressure self-monitoring works best when people are well-supported

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Why was this study needed?

More than one in four adults in England has high blood pressure. This is defined as more than 140/90mmHg on at least two occasions. High blood pressure increases the risk of cardiovascular diseases such as heart failure and stroke that cost the NHS over £2.1bn every year.

Lifestyle measures such as reducing salt in the diet, stopping smoking and regular exercise can reduce blood pressure. A stepped approach to adjust medication against blood pressure is also recommended. However, there can be issues with adherence to both of these treatment strategies.

This review explored whether people monitoring their own blood pressure reduced their levels over a year.

What did this study do?

This systematic review and meta-analysis included individual patient data from 25 randomised controlled trials of blood pressure self-monitoring for 10,487 people with hypertension. All studies were from high-income countries and six were from the UK.

The analysis compared usual care where blood pressure is regularly monitored in a clinic, with usual care plus self-monitoring. It also looked at whether different levels of professional support affected outcomes. The frequency of self-monitoring varied across studies from daily to monthly with most three times per week.

The studies were of reasonable quality with a low risk of bias. However, only 12 studies blinded assessors to participants’ groups. Additionally, there was wide variability between studies. These factors reduce our confidence in the size of this effect, but perhaps not its direction.

What did it find?

By 12 months:

  • Overall, self-monitoring caused a small reduction in systolic blood pressure compared with usual care (mean difference [MD] ‑3.24mmHg, 95% confidence interval [CI] ‑4.92 to ‑1.57; 6,300 participants). It also slightly reduced diastolic blood pressure (MD ‑1.50mmHg, 95% CI ‑2.24 to ‑0.75, 6,300 participants).
  • Self-monitoring reduced the risk of uncontrolled blood pressure by 30% compared with usual care (relative risk [RR] 0.70, 95% CI 0.56 to 0.86, 6,300 participants).
  • Compared with usual care, self-monitoring plus telephone or other counselling was most effective at reducing systolic blood pressure (MD ‑6.10mmHg, 95% CI ‑9.02 to ‑3.18) and diastolic blood pressure (MD ‑2.32mmHg, 95% CI ‑4.04 to ‑0.59). It also reduced the risk of having uncontrolled blood pressure by 56% compared with usual care (RR 0.44, 95% CI 0.34 to 0.57).
  • The next best combination was web/phone feedback with education. Web/phone feedback without education slightly reduced systolic blood pressure but did not reduce diastolic or uncontrolled blood pressure.
  • Self-monitoring with no professional feedback did not reduce systolic, diastolic or uncontrolled blood pressure compared with usual clinic monitoring.

What does current guidance say on this issue?

The NICE 2016 guideline on managing hypertension in adults recommends people are encouraged to monitor their condition. It does not provide advice on whether to use a home blood pressure machine or how frequently to record measurements. An annual review is recommended for support and to assess medication. There is no specific guidance on more frequent counselling and support for home blood pressure measurements unless medication is being altered to get blood pressure under control.

What are the implications?

This review suggests that home blood pressure monitoring is better than usual clinic-based monitoring when accompanied by sufficient support. Understanding the costs involved would be important for commissioners considering implementing such a service.

It remains unclear how frequently the measurements need to be taken and if there are certain groups of people for whom it is more successful. The study does support the idea of giving people more control over their own health.

The researchers plan to analyse the data further to see if there is also an impact on outcomes such as stroke and quality of life.

Citation and Funding

Tucker KL, Sheppard JP, Stevens R, et al. Self-monitoring of blood pressure in hypertension: a systematic review and individual patient data meta-analysis. PLoS Med. 2017;14(9):e1002389.

This project was funded by the Institute for Health Research School for Primary Care Research (NIHR SPCR number 112) and via an NIHR Professorship for Richard McManus (NIHR-RP-02-12-015).

 

Bibliography

NHS Choices.  High blood pressure (hypertension): diagnosis. London: Department of Health; updated 2016.

NICE. Hypertension in adults: diagnosis and management. CG127. London: National Institute for Health and Care Excellence; 2016.

Why was this study needed?

More than one in four adults in England has high blood pressure. This is defined as more than 140/90mmHg on at least two occasions. High blood pressure increases the risk of cardiovascular diseases such as heart failure and stroke that cost the NHS over £2.1bn every year.

Lifestyle measures such as reducing salt in the diet, stopping smoking and regular exercise can reduce blood pressure. A stepped approach to adjust medication against blood pressure is also recommended. However, there can be issues with adherence to both of these treatment strategies.

This review explored whether people monitoring their own blood pressure reduced their levels over a year.

What did this study do?

This systematic review and meta-analysis included individual patient data from 25 randomised controlled trials of blood pressure self-monitoring for 10,487 people with hypertension. All studies were from high-income countries and six were from the UK.

The analysis compared usual care where blood pressure is regularly monitored in a clinic, with usual care plus self-monitoring. It also looked at whether different levels of professional support affected outcomes. The frequency of self-monitoring varied across studies from daily to monthly with most three times per week.

The studies were of reasonable quality with a low risk of bias. However, only 12 studies blinded assessors to participants’ groups. Additionally, there was wide variability between studies. These factors reduce our confidence in the size of this effect, but perhaps not its direction.

What did it find?

By 12 months:

  • Overall, self-monitoring caused a small reduction in systolic blood pressure compared with usual care (mean difference [MD] ‑3.24mmHg, 95% confidence interval [CI] ‑4.92 to ‑1.57; 6,300 participants). It also slightly reduced diastolic blood pressure (MD ‑1.50mmHg, 95% CI ‑2.24 to ‑0.75, 6,300 participants).
  • Self-monitoring reduced the risk of uncontrolled blood pressure by 30% compared with usual care (relative risk [RR] 0.70, 95% CI 0.56 to 0.86, 6,300 participants).
  • Compared with usual care, self-monitoring plus telephone or other counselling was most effective at reducing systolic blood pressure (MD ‑6.10mmHg, 95% CI ‑9.02 to ‑3.18) and diastolic blood pressure (MD ‑2.32mmHg, 95% CI ‑4.04 to ‑0.59). It also reduced the risk of having uncontrolled blood pressure by 56% compared with usual care (RR 0.44, 95% CI 0.34 to 0.57).
  • The next best combination was web/phone feedback with education. Web/phone feedback without education slightly reduced systolic blood pressure but did not reduce diastolic or uncontrolled blood pressure.
  • Self-monitoring with no professional feedback did not reduce systolic, diastolic or uncontrolled blood pressure compared with usual clinic monitoring.

What does current guidance say on this issue?

The NICE 2016 guideline on managing hypertension in adults recommends people are encouraged to monitor their condition. It does not provide advice on whether to use a home blood pressure machine or how frequently to record measurements. An annual review is recommended for support and to assess medication. There is no specific guidance on more frequent counselling and support for home blood pressure measurements unless medication is being altered to get blood pressure under control.

What are the implications?

This review suggests that home blood pressure monitoring is better than usual clinic-based monitoring when accompanied by sufficient support. Understanding the costs involved would be important for commissioners considering implementing such a service.

It remains unclear how frequently the measurements need to be taken and if there are certain groups of people for whom it is more successful. The study does support the idea of giving people more control over their own health.

The researchers plan to analyse the data further to see if there is also an impact on outcomes such as stroke and quality of life.

Citation and Funding

Tucker KL, Sheppard JP, Stevens R, et al. Self-monitoring of blood pressure in hypertension: a systematic review and individual patient data meta-analysis. PLoS Med. 2017;14(9):e1002389.

This project was funded by the Institute for Health Research School for Primary Care Research (NIHR SPCR number 112) and via an NIHR Professorship for Richard McManus (NIHR-RP-02-12-015).

 

Bibliography

NHS Choices.  High blood pressure (hypertension): diagnosis. London: Department of Health; updated 2016.

NICE. Hypertension in adults: diagnosis and management. CG127. London: National Institute for Health and Care Excellence; 2016.

Self-monitoring of blood pressure in hypertension: A systematic review and individual patient data meta-analysis

Published on 19 September 2017

R McManus, K Tucker, J. Sheppard, R Stevens, H. Bosworth,A Bove, E Bray, K Earle, J George, M Godwin,B. Green, P Hebert, R Hobbs, I Kantola

PLoS Medicine , 2017

Background Self-monitoring of blood pressure (BP) appears to reduce BP in hypertension but important questions remain regarding effective implementation and which groups may benefit most. This individual patient data (IPD) meta-analysis was performed to better understand the effectiveness of BP self-monitoring to lower BP and control hypertension. Methods and findings Medline, Embase, and the Cochrane Library were searched for randomised trials comparing self-monitoring to no self-monitoring in hypertensive patients (June 2016). Two reviewers independently assessed articles for eligibility and the authors of eligible trials were approached requesting IPD. Of 2,846 articles in the initial search, 36 were eligible. IPD were provided from 25 trials, including 1 unpublished study. Data for the primary outcomes—change in mean clinic or ambulatory BP and proportion controlled below target at 12 months—were available from 15/19 possible studies (7,138/8,292 [86%] of randomised participants). Overall, self-monitoring was associated with reduced clinic systolic blood pressure (sBP) compared to usual care at 12 months (−3.2 mmHg, [95% CI −4.9, −1.6 mmHg]). However, this effect was strongly influenced by the intensity of co-intervention ranging from no effect with self-monitoring alone (−1.0 mmHg [−3.3, 1.2]), to a 6.1 mmHg (−9.0, −3.2) reduction when monitoring was combined with intensive support. Self-monitoring was most effective in those with fewer antihypertensive medications and higher baseline sBP up to 170 mmHg. No differences in efficacy were seen by sex or by most comorbidities. Ambulatory BP data at 12 months were available from 4 trials (1,478 patients), which assessed self-monitoring with little or no co-intervention. There was no association between self-monitoring and either lower clinic or ambulatory sBP in this group (clinic −0.2 mmHg [−2.2, 1.8]; ambulatory 1.1 mmHg [−0.3, 2.5]). Results for diastolic blood pressure (dBP) were similar. The main limitation of this work was that significant heterogeneity remained. This was at least in part due to different inclusion criteria, self-monitoring regimes, and target BPs in included studies. Conclusions Self-monitoring alone is not associated with lower BP or better control, but in conjunction with co-interventions (including systematic medication titration by doctors, pharmacists, or patients; education; or lifestyle counselling) leads to clinically significant BP reduction which persists for at least 12 months. The implementation of self-monitoring in hypertension should be accompanied by such co-interventions.

Expert commentary

Effective lowering of high blood pressure significantly prevents strokes and heart attacks. Encouraging individuals with hypertension to be more involved in their healthcare by self-monitoring of their blood pressure may increase their adherence to medication and improve hypertension control.

The results of this study emphasise, not only self-monitoring of blood pressure, but also the crucial role of healthcare professionals (doctors, nurses, and pharmacists) in assembling a management plan and clear guidance for patients to follow when their blood pressure is not well controlled to target. This guidance may involve titration of the patients’ medications in a well-defined stepped-up strategy, and other lifestyle changes.

Dr Tarek Francis Antonios, Senior Lecturer & Consultant Physician in Cardiovascular & General Medicine, Head of Blood Pressure Unit, St. George's Hospital, University of London