A small Canadian study suggests that readings from home blood pressure monitors devices are wrong most of the time and could put patients at risk.
A research team from the University of Alberta in Calgary, testing dozens of home monitors used by 85 patients, found the units weren’t accurate within five mmHg of blood pressure about 70 per cent of the time. The investigators added the devices were off the mark by at least 10 mmHg about 30 per cent of the time.
Research team leader Jennifer Ringrose said such an inaccuracy could have serious consequences for people’s health. The group tested averaged 66 years of age. “Monitoring for and treating high blood pressure can lower the consequences of this disease,” she said. “We need to make sure that home blood pressure readings are accurate.”
Should people who have bought and use these monitors toss them out? Maybe not. Ringrose says there are a number of ways to minimize such inaccurate readings.
First, she said, “compare the blood pressure machine measurement with a blood pressure measurement in a clinic before exclusively relying upon home readings. What’s really important is to do several blood pressure measurements and base treatment decisions on multiple readings.”
Ringrose says home monitoring can still be very useful because it empowers patients. It is helpful for clinicians to have a bigger picture, rather than just one snapshot in time.” The study was published recently in the American Journal of Hypertension.
Co-author Raj Padwal warns however that patients should not have blood pressure medications started or changed based on one or two measurements taken at a single point in time unless the readings are clearly elevated. Certain factors – inappropriately sized arm cuffs, or patients with a specific type of blood pressure – may combine with inaccurate readings to give some patients a “a false sense of security,” he said.
Patients who use these automated blood pressure devices are urged to take them to their physicians once or even twice to measure their accuracy against an office-based manual measurement.