December 11, 2010
Monitoring Blood Pressure At Home
Home blood pressure monitors may help people keep their blood pressure in check and possibly reduce their medications -- but only if patients and their physicians put those home readings to good use, according to findings in a new research review.
Analysis of 37 international clinical trials found that on average, adults with high blood pressure who were assigned to use home monitors were able to cut down their blood pressure by a few points compared to those who stuck with doctor's office visits to get their readings.The home monitor users were also twice as likely to reduce the number of blood pressure medications they needed.
Researchers said the findings should encourage people with high blood pressure to invest in home monitors. The devices generally range from about $25 to over $100, depending on model and features.
"Everyone who wants to know how well (their) blood pressure is controlled should monitor blood pressure at home," the study's lead author, Dr. Rajiv Agarwal of the Indiana University School of Medicine in Indianapolis, told Reuters Health by email.
He said, however, that blood pressure monitors are like treadmills. People buy them with good intentions, but how they use them is what matters.
In the study, Agarwal and colleagues found that home monitoring tended to work better when it was part of a general plan to lower medications if readings were good.
A few studies Agarwal's team reviewed tested so-called telemonitoring, in which wired technology is used to automatically send BP readings to the doctor's office. Those studies tended to show greater effects on blood-pressure control than studies using traditional BP monitors.
Currently, though, telemonitoring is not commonly used and studies are still investigating its value.
The findings from the trials included a total of 9,446 men and women with high BP. Researchers randomly assigned some patients to use home monitors and the rest to stay with office-based measurements. Most of the studies followed patients for 2 months up to one year.
Overall, home monitor users saw their BP drop by 2 to 3 points, and most studies came out in favor of home monitoring over office-based monitoring alone -- though the differences were generally small.
Patients using home monitors were also more likely to reduce their medications. In one of the larger trials, 51 out of 203 home-monitor patients reduced their number of medications, versus 22 of 197 patients who didn't use home monitors.
Agarwal's team believed those results may be because home monitoring helps detect the "white coat effect" -- when a person's blood pressure spikes in the doctor's office.
Dr. Giuseppe Mancia, who co-wrote an editorial published with the study, agreed that home monitors are a good investment.
"I definitely believe that all (high blood pressure) patients should be advised by their physician to use a home BP monitor," Mancia, of the University of Milano-Bicocca in Italy, told Reuters Health in an e-mail.
Mancia pointed out, however, that patients should use the monitors only as often as their doctors recommend, and not become obsessive about checking their numbers. Obsessive monitoring may spur anxiety, which could boost blood pressure.
People should also be sure to choose monitors that have been validated for accuracy according to international criteria, he said.
The current study, reported in the journal Hypertension, was funded by the US Department of Veterans Affairs. None of the researchers reports any financial conflicts of interest.
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