Home monitoring helps lower blood pressure

Posted: 9th August 2013

Tracking blood pressure at home helped patients with hypertension keep it under control, at least over the short term, a meta-analysis determined.

Pooled study results pointed to 3.9/2.4 mm Hg lower blood pressure on average with self-monitoring at 6 months compared with usual care based on in-clinic monitoring alone, Katrin Uhlig, MD, of Tufts Medical Center in Boston, and colleagues found.

That impact "would be clinically relevant on a population level if they were sustained over time," the researchers wrote online in the Annals of Internal Medicine.

"For example, a decrease of 2 or 5 mm Hg in systolic blood pressure in the population has been estimated to result in mortality reductions of 6% or 14% due to stroke, 4% or 9% due to chronic heart disease, and 3% or 7% due to all causes," they explained.

While the impact of home monitoring alone fizzled to a nonsignificant 1.5/0.8 mm Hg reduction by 12 months, additional support, like education or counseling, kept the effect going.

Long-term studies were sparse, though, so more research is needed to sort out the effect on blood pressure control beyond 12 months, Uhlig's group noted.

The Agency for Healthcare Research and Quality commissioned their comparative-effectiveness review on self-monitoring blood pressure, which guidelines recommend for known or suspected hypertension.

The meta-analysis included 52 prospective comparative studies of self-measured blood pressure monitoring, whether with additional support or not, compared against usual care or an alternative self-monitored blood pressure intervention in people with hypertension.

Studies in dialysis or gestational hypertension were excluded, as were those looking at self-monitoring as a component of heart failure disease management or a weight-loss program and those that used less reliable wrist monitors.

About half of the studies used additional support with self-monitoring, ranging from educational materials to telecounseling, phone monitoring with electronic transmission of blood pressure data, or nurse or pharmacist visits.

These 25 studies showed a greater reduction in blood pressure by 3.4 to 8.9 mm Hg systolic and 1.9 to 4.4 mm Hg diastolic with self-monitoring plus additional support compared with usual clinic-based monitoring alone in up to 12 months of follow-up.

Longer follow-up yielded mixed results, with one high-quality study finding no impact at 18 months but two others indicating a significant impact at 24 to 60 months compared with usual care.

The 13 trials that compared self-monitored blood pressure either alone versus with additional support or with more versus less intense additional support were of generally lower quality.

And because only three showed a significant benefit to additional or more intensive support, the researchers concluded that the evidence failed to support a difference, though noting that "overall there is a suggestion that additional support is synergistic with self-measured blood pressure monitoring to achieve blood pressure control."

Other surrogate measures -- typically medication use, quality of life, adherence, and healthcare visits -- turned out inconclusive due to inconsistent results and low-strength evidence.

Only one of the 52 studies looked at clinical outcomes.

Limitations included heterogeneity in protocols for self-measured blood pressure monitoring, for additional support, for blood pressure targets, and for management as well as the relatively short follow-up of 1 year or less in most of the studies. Also, many studies were low quality and likely underpowered.

Finally, the results would only apply to uncomplicated hypertension in adults without recent acute illness who are willing and able to monitor their blood pressure at home, the researchers noted.


Source: Medpage Today. Read more here.

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