Warning over inaccurate blood pressure monitors


Home devices: People using blood pressure monitors at home have been warned that many of the devices are inaccurate and could be giving misleading readings.

The devices can be freely bought in a number of outlets, including discount stores, pharmacies and through mail order schemes. Costs vary wildly, depending on the outlet, with patients paying anything from €50 to €150.

Many pharmacies stock monitors that have been validated but customers should still check that this is the case.

Prof Eoin O'Brien, professor of Cardiovascular Pharmacology at the Royal College of Surgeons told The Irish Times that there was "considerable concern" about the home kits.

"Many of the blood pressure monitoring devices are brought out by manufacturers without any independent assessment of them," he said.

There is no legal obligation on manufacturers to have their devices validated and because this rigorous clinical testing can take up to two years, many manufacturers do not seek validation.

"A lot of gimmicky devices are produced and they can give rather inaccurate readings," Prof O'Brien said.

This could have two serious implications. Patients could believe that their blood pressure is normal when in fact it is too high, or they could take medication for high blood pressure when they do not need it.

Prof O'Brien chairs the European Society of Hypertension's blood pressure monitoring committee and has written extensively on the subject.

He is one of the founders of a website (www.dableducational.org) which reviews blood pressure monitoring devices. Visitors to the website can check if their blood pressure monitors are recommended or not.

Prof O'Brien was the co-author of an editorial in the British Medical Journal last October which advised that "few of the devices available on the market are accurate. Wrist and finger devices are not recommended."

Properly validated home blood pressure monitors, when used correctly, have an advantage over doctor-measured blood pressure hospital tests as they help to eliminate the "white coat hypertension" syndrome.

This arises when a patient's blood pressure increases because of the stress of having the measurement in a clinical setting. Regular testing at the same time over a set period at home could yield more accurate results, researchers say.

Faulty kits could be a matter of life or death, according to Mr Liam Murray, pharmacist and director of a medical equipment distribution company.

He recently helped to provide a blood pressure monitoring service at a health awareness forum for the over-50s at the RDS.

Three people were greatly alarmed at the wide divergence between the reading in the RDS and the reading they had received from their home blood pressure monitors.

Mr Murray said one woman's blood pressure was critical. "She was at risk of having a stroke in the near term. She had a blood pressure monitor at home and she told me the readings. They were way, way, below that reading. I advised her to go to her GP immediately," he said.

Mr Murray said safety standards should be mandatory for such medical items. "It's not like buying a toaster. There are a lot of unreliable blood pressure monitors about.

"Blood pressure is one of the principal tools in assessing the health of a patient. Any mis-information in this area is a serious matter."

He said the use of the home devices was "extremely useful and a very positive development" but the devices must be reliable.

Mr Madden recommended that people only buy from an informed source which has proven access to a testing facility. "And even then, they should make sure that the monitor is stamped "Validated", he said.

People should then have their device regularly checked to ensure that it was still reliable, he added.