Q: Before I buy one, do you have any information on how accurate those blood pressure monitors you wear on your wrist are?
M.A., of Fairview Heights
A: If you splurge on this personal high-tech medical device, you’re urged to talk to your physician about the proper way to use it — and follow those instructions exactly. They can be quite accurate, but unless you use them correctly, you may be lulled into a false sense of security — or panicked by a false sense of alarm.
In a recent study, 720 people were trained how to use the devices. Even so, doctors found that 620 of them took inaccurate readings and 433 were off by at least 10 mm/hg, a large error.
In the study published in Hypertension Journal, authors warned the wrist must be positioned just right or the reading will be prone to error. If, for example, the device is placed below heart level, it can give falsely high levels. They concluded that even after a training course, age and education levels seem to show that monitors may not be for everyone.